Pls Help I am stuck on this and i don't know how to do this

Rounding to three decimal places, the probability that exactly 7 Americans out of a sample of 15 own an answering machine is approximately 0.170.

To find the probability that exactly 7 of the 15 Americans selected at random own an answering machine, we can use the binomial distribution formula:

P(X = k) = (n choose k) * p^k * (1 - p)^(n - k)

where P(X = k) is the probability of getting exactly k successes, n is the sample size, p is the probability of success, and (n choose k) is the binomial coefficient which represents the number of ways to choose k successes out of n trials.

In this case, n = 15, p = 0.69 (the proportion of Americans who own an answering machine), and k = 7. Thus, the probability of getting exactly 7 Americans who own an answering machine out of a sample of 15 is:

P(X = 7) = (15 choose 7) * 0.69^7 * (1 - 0.69)^(15 - 7)

Using a calculator or statistical software, we can evaluate this expression to find:

P(X = 7) ≈ 0.170

This means that if we were to repeat this survey many times with samples of size 15, we would expect approximately 17% of the samples to have exactly 7 Americans who own an answering machine.

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a force of 560J can raise a block weighing 8 N to a height of 70 meters. It's important to note that this calculation assumes no energy is lost due to friction or other factors, so in reality, the block may not reach exactly 70 meters.

How to calculate work?

To calculate the height to which a block weighing 8 N can be raised by a force of 560J, we need to use the formula for work done:

Work (W) = force (F) x distance (d) x cos(theta)

where theta is the angle between the force and the displacement. In this case, the force is the weight of the block (8 N), the distance is the height the block is raised (h), and theta is 0 degrees because the force is acting vertically upward and the displacement is in the same direction.

So, we can rearrange the formula to solve for the height (h):

h = W / (F x cos(theta))

Substituting the values we have, we get:

h = 560 J / (8 N x cos(0 degrees))

Since the cosine of 0 degrees is 1, we can simplify to:

h = 560 J / 8 N

h = 70 meters

Therefore, a force of 560J can raise a block weighing 8 N to a height of 70 meters. It's important to note that this calculation assumes no energy is lost due to friction or other factors, so in reality, the block may not reach exactly 70 meters.

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To solve an equation with multiple unknowns, you need to have as many equations as there are unknowns.the solution to the system of equations is  [tex]x = 13/11 and z = 37/11.[/tex]

For the equation you provided, [tex]-x - 4z = -15[/tex]  , there are two unknowns: x and z. To solve for both, you need another equation that involves x and z.

If you have another equation that involves x and z, you can use a method like substitution or elimination to solve for both variables simultaneously.

For example, let's say you have the equation  [tex]2x + 3z = 7.[/tex] You can use substitution to solve for one variable in terms of the other and substitute the result into the other equation.

To solve for x, rearrange the first equation to get x in terms of z:

[tex]-x - 4z = -15[/tex]

[tex]x = -15 + 4z[/tex]

Substitute the expression for x into the second equation:

[tex]2x + 3z = 7[/tex]

[tex]2(-15 + 4z) + 3z = 7[/tex]

Distribute the 2:

[tex]-30 + 8z + 3z = 7[/tex]

Simplify:

[tex]11z = 37[/tex]

Solve for z:

[tex]z = 37/11[/tex]

Substitute the value of z back into the equation for x:

[tex]x = -15 + 4z[/tex]

[tex]x = -15 + 4(37/11)[/tex]

[tex]x = -15 + 148/11[/tex]

Simplify:

[tex]x = 13/11[/tex]

Therefore, the solution to the system of equations is x = 13/11 and z = 37/11.

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Answer:

Step-by-step explanation:

Answer:

The first one...............

The quadratic equation x² + 2 - 4x = -4 in standard form is  x² - 4x + 6 = 0

A quadratic equation in standard form is given by ax² + bx + c = 0

Now, given the equation x² + 2 - 4x = -4, we desire to write it in standard form, we proceed as follows.

Since we have the quadratic equation x² + 2 - 4x = -4 writing it in standard form, we have

x² + 2 - 4x = -4

Adding 4 to both sides of the equation, we have that

x² + 2 - 4x + 4 = -4 + 4

x² + 2 + 4 - 4x = 0

x² + 6 - 4x = 0

Re-arranging, we have that

x² - 4x + 6 = 0

So, in equation in standard form is  x² - 4x + 6 = 0

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The roots of the given quadratic equation are x= 4, [tex]\frac{-3}{2}[/tex]

The definition of a quadratic as a second-degree polynomial equation demands that at least one squared term must be included. It also goes by the name quadratic equations. The quadratic equation has the following generic form:

ax² + bx + c = 0The roots of a quadratic equation are found using the quadratic formula. In place of the factorization method, this formula aids in evaluating the quadratic equations' solutions. The quadratic formula aids in identifying the problem's fictitious roots when a quadratic equation lacks actual roots. Shreedhara Acharya's formula is another name for the quadratic formula.

2x² - 5x​ -12 = 0

The Shridharacharya formula or quadratic formula -

[tex]x=\frac{-b\ +-\sqrt{b^2-4ac}}{2a}[/tex]

we have a=2, b=-5 and c=-12

[tex]x=\frac{5+-\sqrt{5^2-4*2*12}}{2*2}\\\\x=\frac{5+-\sqrt{25+96}}{4}\\\\x=\frac{5+\sqrt{121}}{4}\\\\x=\frac{5+-11}{4}\\now, \\x=\frac{5+11}{4}=\frac{16}{4}\\x=4\\x=\frac{5-11}{4}\\x=-6/4\\x=-3/2[/tex]

The mistake in your solution is we have the value of b=-5 so , when we put the value of b in a formula then -5 will be 5.

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Answer:

8.17

Step-by-step explanation:

43x19/100 equals 8.17

Answer:

B. y = (x+1)(x-3)

Step-by-step explanation:

Bbecause when y intersect the x axis, y = 0

so (x+1)(x-3) = 0, which we get x = -1 and x = 3

As shown in the graph this is true, because the function does indeed also intersect with the x axis at x = -1 and x = 3 as well.

Answer: 81 ham subs

Step-by-step explanation:

4 times 9 is 36. That means you have to multiply 9 by 9, to get 81 ham subs. The ratio is 81:36. :)

The answer is 23/40

To simplify this expression, we need to find a common denominator for each pair of fractions that are being added or subtracted.

 
The common denominator for 1/4 and 1/5 is 20, so we can rewrite 1/4 as 5/20 and 1/5 as 4/20. Then, we can subtract these fractions to get 1/20.

 
The common denominator for -3/4 and 1/8 is 8, so we can rewrite -3/4 as -6/8. Then, we can add these fractions to get -5/8.

 
Now, we can combine the two simplified fractions by finding a common denominator of 40. We can do this by multiplying 20 and 8, which gives us 160.

Then, we can rewrite 1/20 as 2/40 and -5/8 as -25/40. Adding these fractions together gives us:

2/40 - 25/40 = -23/40.

The absolute value of any number is always positive so it becomes 23/40.

The simplified version of (1/4 - 1/5) + (-3/4 + 1/8) is 23/40.

The correlation between the ages of men and women in this situation would be +1. This means that for every one-year increase in the age of the man, the age of the woman would increase by one year as well. The correlation coefficient of +1 signifies a perfect positive linear correlation between the two variables.

In other words, if a man is 40 years old, the woman he is married to would be 37. If the man was 50, then the woman would be 47, and so on. This would remain true for any age, regardless of the difference in their ages. Therefore, the correlation between their ages would always remain +1.

It is important to note that this correlation coefficient is not necessarily reflective of  traditional or even natural social or biological behavior. Rather, it is simply a mathematical relationship that would exist in this specific situation. In reality, the age gap between married couples can vary widely depending on various social and cultural factors.

To summarize, the correlation between the ages of men and women in this scenario would be +1, signifying a perfect positive linear correlation. This means that for any given age of the man, the age of the woman would be exactly three years younger.

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The fact that the overall frequency of an event can be determined by multiplying together the frequencies of the independently occurring factors related to that event is called a frequency multiplier. Also called as multiplication rule.

             The multiplication rule states that the overall probability of a sequence of events happening jointly is the product of the probabilities of the individual events.

                  In probability, the multiplication rule is used to calculate the joint probability of two independent events that occur together.

              In probability scenarios, the factors are the set of conditions that influence the probability of a certain occurrence, event, or outcome.

These factors are used to calculate the probability of an event. The likelihood of the occurrence of an event is based on these factors.

             The multiplication rule can be used to calculate the overall frequency of an event by multiplying the frequency of each factor independently related to the event.

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To simulate the minutes between customer arrivals in Excel, one would use the Exponential distribution function in Excel.

This function is part of the Statistical functions category and can be found under the "Statistical" tab in Excel.

An exponential distribution is a probability distribution that describes the time between events in a Poisson process, where events occur continuously and independently at a constant average rate.

The Exponential distribution function in Excel takes two arguments: Lambda and x.

Lambda is the rate parameter, which describes the average number of events per unit of time.

In this case, the rate is 6 customers per hour, so Lambda would be equal to 6.

X is the time interval, and in this case, it would be the time between customer arrivals in minutes.

Therefore, to simulate the minutes between customer arrivals, one would use the following formula in Excel: =EXPON.DIST(x/60,1/6,TRUE)

The "x/60" part of the formula is used to convert the time interval from minutes to hours, as the rate is given in customers per hour.

The "1/6" part of the formula is used to set the Lambda value to 6.

The "TRUE" part of the formula is used to specify that we want the cumulative distribution function (CDF), which gives the probability that the time between events is less than or equal to x.

To simulate the minutes between customer arrivals in Excel, we would use the Exponential distribution function with Lambda = 6 and x being the time interval between customer arrivals in minutes.

The formula would be = EXPON.DIST(x/60,1/6,TRUE).

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Answer:

y- intercept = 18

Step-by-step explanation:

the equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

y = - 3x + 8 ← is in slope- intercept form

with slope m = - 3

• Parallel lines have equal slopes , then

y = - 3x + c ← is the partial equation

to find c substitute (5, 3 ) into the partial equation

3 = - 3(5) + c = - 15 + c ( add 15 to both sides )

18 = c

y = - 3x + 18 ← equation of parallel line

with y- intercept c = 18

Answer:

Step-by-step explanation:

Let's call the length of the shorter leg of the isosceles trapezoid "a" and the length of the longer leg "b".

From the problem, we know that:

a = 0.1x - 0.5 (length of one leg is 0.1.x - 0.5 meters)

b = 0.3x - 2.1 (length of the other leg is 0.3.x-2.1 meters)

Since we know that the trapezoid is isosceles, we know that a = b. So we can set the two expressions equal to each other:

0.1x - 0.5 = 0.3x - 2.1

Now we can solve for x:

0.2x = 1.6

x = 8

Now that we know x, we can substitute it back into the expressions for a and b to find their lengths:

a = 0.1(8) - 0.5 = 0.3 meters

b = 0.3(8) - 2.1 = 0.3 meters

Therefore, each of the legs of the solar panel are 0.3 meters long.

Answer:

Proofs attached to answer

Step-by-step explanation:

Proofs attached to answer

it would take 6 men 20 minutes to dig a hole that is 4 x 4 x 3 meters

To solve this problem, we can use the formula that relates the time taken to do a job to the number of workers available, assuming that all workers have the same productivity. This formula is given by the equation:Work Done = Productivity x Time Taken x Number of Workers available. If we let the work done be W, the productivity be P, and the time taken be T, then the equation becomes:W = P x T x N. We are given that 3 men can dig a hole that is 3 x 2 x 4 meters in 20 minutes. We can find the volume of this hole by multiplying its dimensions:V = 3 x 2 x 4 = 24 cubic metersThis means that 3 men can dig a volume of 24 cubic meters in 20 minutes.

To find their productivity, we can use the formula: Productivity = Work Done / (Time Taken x Number of Workers)P = W / (T x N) = 24 / (20 x 3) = 0.4 cubic meters per minute per worker. Now we can use this productivity to find the time taken for 6 men to dig a hole that is 4 x 4 x 3 meters. We can find the volume of this hole by multiplying its dimensions:V = 4 x 4 x 3 = 48 cubic meters.

To dig this hole, the amount of work done would be 48 cubic meters. The productivity per worker is still 0.4 cubic meters per minute, but the number of workers is now 6. Therefore, the time taken would be:T = W / (P x N) = 48 / (0.4 x 6) = 20 minutes.Therefore, it would take 6 men 20 minutes to dig a hole that is 4 x 4 x 3 meters, given that 3 men can dig a hole that is 3 x 2 x 4 meters in 20 minutes.

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The numerical value of x in the expression (x+5) and 2(x-4) is 61.

The sum of angles on a straight line equals 180 degrees.

From the figure in the image:

We know that the sum of angles on a straight line equals 180 degrees.

Since angle GDC and its supplement are on a straight line.

Hence;

Angle GDC + Supplemetary angle to GDC = 180

Plug in the given values and solve for x.

( x + 5 ) + 2( x - 4 ) = 180

Apply distributive property.

x + 5 + 2x - 8 = 180

Collect like terms

x + 2x - 8 + 5 = 180

3x - 3 = 180

3x = 180 + 3

3x = 183

x = 183/3

x = 61

Therefore, the value of x is 61.

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Answer:

Step-by-step explanation:

Replacing it

(a) The area of the triangle is 16 square units.

(b) The area of the triangle is 54 square units.

(c) the area of the quadrilateral is 20 square units.

(d) The area of the triangle is 12.5 square units.

(a) To find the area of the triangle with vertices (0,0), (3,7), and (5,1), we can use the formula:

A = 1/2 | x1(y2 - y3) + x2(y3 - y1) + x3(y1 - y2) |

Plugging in the values, we get:

A = 1/2 | 0(7 - 1) + 3(1 - 0) + 5(0 - 7) |

= 1/2 | 0 + 3 - 35 |

= 1/2 |-32|

= 16

(b) To find the area of the triangle with vertices (-4,2), (0,-8), and (5,11), we can again use the same formula:

A = 1/2 | x1(y2 - y3) + x2(y3 - y1) + x3(y1 - y2) |

Plugging in the values, we get:

A = 1/2 | (-4)(-8 - 11) + (0)(11 - 2) + (5)(2 - (-8)) |

= 1/2 | 108 |

= 54

(c) To find the area of the quadrilateral with vertices (-2,-4), (3,1), (-1,5), and (6,-3), we can divide it into two triangles and find the area of each triangle.

We can use the formula for the area of a triangle:

A = 1/2 | x1(y2 - y3) + x2(y3 - y1) + x3(y1 - y2) |

For the triangle with vertices (-2,-4), (3,1), and (-1,5), we get:

A1 = 1/2 | (-2)(1 - 5) + (3)(5 + 4) + (-1)(-4 - 1) |

= 1/2 | (-8 + 35 + 5) |

= 16

For the triangle with vertices (3,1), (-1,5), and (6,-3), we get:

A2 = 1/2 | (3)(5 + 3) + (-1)(-3 - 1) + (6)(1 - 5) |

= 1/2 | (24 + 4 - 20) |

= 4

Therefore, the area of the quadrilateral is:

A = A1 + A2

= 16 + 4

= 20 square units

(d) To find the area of the triangle with vertices (-1,-2), (-2,3), and (4,-4), we can use the same formula:

A = 1/2 | x1(y2 - y3) + x2(y3 - y1) + x3(y1 - y2) |

Plugging in the values, we get:

A = 1/2 | (-1)(3 + 4) + (-2)(-4 + 2) + (4)(-2 - 3) |

= 1/2 | (-7 - 4 - 14) |

= 12.5

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To test if more than 80% of her students enjoyed taking her class, the statistics professor should use a hypotheses test.

The null hypotheses (H0) would be that the proportion of students who enjoyed taking her class is equal to or less than 80%, while the alternative hypothesis (Ha) would be that the proportion is greater than 80%.

H0: p <= 0.80

Ha: p > 0.80

Where p: proportion of students who enjoyed taking the class.

To test this hypothesis, the professor would need to collect a random sample of students from her class and ask them if they enjoyed taking the class. She could then use a test statistic, such as the z-score, to determine the probability of obtaining the observed proportion of students who enjoyed the class, assuming the null hypothesis is true.

If the probability of obtaining the observed proportion is very low (typically, less than 0.05), then the professor would reject the null hypothesis and conclude that there is evidence to support the alternative hypothesis that more than 80% of her students enjoyed taking her class.

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Answer:

10km/hr

Step-by-step explanation:

The speed of the wind is approximately 6.93 km/hr.

We have,

Let's call the speed of the wind "w" (in km/hr).

When the airship is flying with the wind, its speed relative to the ground is the sum of its speed in calm weather (50 km/hr) and the speed of the wind (w km/hr). So the airship's speed with the wind is 50 + w km/hr.

When the airship is flying against the wind, its speed relative to the ground is the difference between its speed in calm weather (50 km/hr) and the speed of the wind (w km/hr).

So the airship's speed against the wind is 50 - w km/hr.

The distance flown by airship in each direction is the same (150 km).

Let's use the formula for distance, rate, and time:

distance = rate x time

For the first leg of the trip (flying with the wind), we have:

distance = (50 + w) x time

distance = (50 + w) x t(1)

where t(1) is the time taken for the first leg of the trip.

For the second leg of the trip (flying against the wind), we have:

distance = (50 - w) x time

distance = (50 - w) x t(2)

where t(2) is the time taken for the second leg of the trip.

The total time for the round trip is given as 6 hours and 15 minutes, or 6.25 hours.

So we have:

t(1) + t(2) = 6.25

We also know that the distance flown in each direction is 150 km. So we have:

(50 + w) x t(10 = 150

(50 - w) x t(2) = 150

Now we can solve this system of equations for w:

t(1) = 150 / (50 + w)

t(2) = 150 / (50 - w)

t(1) + t(2) = 6.25

Substituting the first two equations into the third equation, we get:

150 / (50 + w) + 150 / (50 - w) = 6.25

Multiplying both sides by (50 + w)(50 - w), we get:

150(50 - w) + 150(50 + w) = 6.25(50 + w)(50 - w)

Expanding and simplifying, we get:

7500 - 150w + 7500 + 150w = 15625 - 312.5w²

Simplifying further, we get:

15000 = 312.5w²

Dividing both sides by 312.5, we get:

w² = 48

Taking the square root of both sides, we get:

w = ±√(48)

Since the speed of the wind cannot be negative, we take the positive square root:

w = √(48) ≈ 6.93 km/hr

Therefore,

The speed of the wind is approximately 6.93 km/hr.

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ARMY DISBANDED MEANS SOLDIERS WERE RELEASED FROM SERVICE

When George Washington became president in 1789, the army he had

commanded in the American Revolution had disbanded. This means that

the soldiers were released from service and the military units were

dissolved after the end of the war.He pursued two intertwined interests:

military arts and western expansion. At 16 he helped survey Shenandoah

lands for Thomas, Lord Fairfax. Commissioned a lieutenant colonel in 1754,

he fought the first skirmishes of what grew into the French and Indian War.

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Answer:

China's top ten famous flowers are: the queen of flowers - plum blossom, the king of flowers - peony, frost blooming - chrysanthemum, gentleman's flower - orchid, the queen of flowers - rose, blooming flowers - Rhododendron, delicate flowers - camellia, water hibiscus - lotus, ten miles of fragrance - osmanthus, Lingbo fairy - daffodil 10 kinds of precious and beautiful local flowers.

Plum blossom is known as the "top ten famous flowers in China". These ten kinds of flowers respectively contain different levels of Chinese spiritual and cultural deposits, with profound and strong historical connotation. They are unique in the flower industry, marking the extraordinary significance of Chinese traditional culture. However, among China's top 10 traditional famous flowers, only the plum blossom, osmanthus and lotus have international registration rights.

the amount of sand in the top cone when the height of the sand is only 1 inch is (h-1)/h times the amount of sand in the top cone originally.

the cones are similar, their volumes are proportional to the cube of their heights. Let's denote the height of the top cone as h, and the radius of the top and bottom bases as r. Then, the volume of the top cone can be expressed as:

V₁ = (1/3)π[tex]r^2[/tex]h

If the height of the sand in the top cone is reduced to 1 inch, then the height of the remaining sand in the top cone is (h-1) inches. The volume of the remaining sand in the top cone can be expressed as:

V₂ = (1/3)π[tex]r^2[/tex](h-1)

To compare the amount of sand in the top cone in these two scenarios, we can take the ratio of their volumes:

V₂/V₁ = [(1/3)π[tex]r^2[/tex](h-1)] / [(1/3)π[tex]r^2[/tex]h] = (h-1)/h

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When n > 30, the sampling distribution of the mean will have a shape of symmetric, the mean will be equal to the population mean (μ), and the standard error will be equal to σ/√n.

The shape of a sampling distribution of the mean is always symmetric when n > 30. This is because the Central Limit Theorem (CLT) states that the sampling distribution of the mean is approximately normal when the sample size is greater than 30. Therefore, when n > 30, the shape of the sampling distribution of the mean will be symmetric.

The mean of the sampling distribution of the mean is equal to the population mean, μ. This is because the sampling distribution of the mean is a probability distribution of all the possible sample means, and it is centered around the population mean. Therefore, the mean of the sampling distribution of the mean is equal to μ.

The standard error (SE) of the sampling distribution of the mean is equal to the population standard deviation (σ) divided by the square root of the sample size (n). This is because the standard error is a measure of how accurately the sample mean estimates the population mean. Since the sample size is greater than 30, the sample mean will accurately estimate the population mean and the standard error will be equal to σ/√n.

In summary, when n > 30, the sampling distribution of the mean will have a shape of symmetric, the mean will be equal to the population mean (μ), and the standard error will be equal to σ/√n.

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True, conditional formulas can be used to exclude data from analysis if certain conditions are met. These formulas, often found in spreadsheet software and programming languages, allow you to set specific criteria that must be met in order for the data to be included or excluded from your analysis.

This can be useful in situations where you need to focus on specific subsets of data, or to remove outliers or irrelevant information from your dataset.

By incorporating conditional logic in your formulas, you can ensure that only relevant and useful data is included in your analysis, making it more accurate and efficient. Overall, the use of conditional formulas can greatly enhance your data analysis by providing a flexible and powerful tool to filter and process your data based on specific requirements.

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Answer:

To solve the inequality x^2-5x-36>0, we need to find the values of x for which the expression is greater than zero.

One way to do this is by factoring the quadratic expression:

x^2-5x-36 = (x-9)(x+4)

The expression is positive when either both factors are positive or both factors are negative.

When both factors are positive: x-9 > 0 and x+4 > 0

Solving for x, we get x > 9 and x > -4. Therefore, x > 9.

When both factors are negative: x-9 < 0 and x+4 < 0

Solving for x, we get x < 9 and x < -4. Therefore, x < -4.

Now, we have two intervals: x < -4 and x > 9. To check whether the expression is positive within these intervals, we can pick a value within each interval and plug it into the expression.

Let's choose x = -5 (within x < -4) and x = 10 (within x > 9).

For x = -5:

x^2-5x-36 = (-5)^2-5(-5)-36

= 25+25-36

= 14

Since 14 is greater than zero, the expression is positive when x = -5.

For x = 10:

x^2-5x-36 = 10^2-5(10)-36

= 100-50-36

= 14

Since 14 is greater than zero, the expression is also positive when x = 10.

Therefore, the solution to the inequality x^2-5x-36>0 is x < -4 or x > 9, which can be written in interval notation as (-∞,-4) ∪ (9,∞).