The sum of the first n terms of an arithmetic sequence is n/2(4n + 20).
a) Write down the expression for the sum of the first (n − 1) terms.
b) Find the first term and common difference of the above sequence.

Answers

Answer 1

Answer:

(a).

[tex]S_{n} = \frac{n}{2} (4n + 20) \\ \\S _{n - 1} = \frac{(n - 1)}{2} (4n - 4 + 20) \\ \\ S _{n - 1} = \frac{(n - 1)}{2} (4n + 16) \\ \\S _{n - 1} = \frac{(n - 1)(4n + 16)}{2} \\ \\ { \boxed{S _{n - 1} = {2 {n}^{2} + 6n - 8}}} \\ [/tex]

(b).

from general equation:

[tex]S _{n - 1} = \frac{(n - 1)}{2} (4n + 16)[/tex]

first term is 4n

common difference:

[tex]16 = \{(n - 1) - 1 \}d \\ 16 = (n - 2)d \\ d = \frac{16}{n - 2} [/tex]


Related Questions

please help me
integrate In x
[tex] \frac{ lnx ^{2} }{x}[/tex]

Answers

Answer:

On the pic

Step-by-step explanation:

Sorry if my handwriting is bad

Answer equation in photo, show work please and thanks

Answers

Answer:

19

Step-by-step explanation:

There are 38 points total, each field goal is 2 points.

If we do 38/2 we get 19.

Image has work...

[tex]\frac{38}{2}[/tex]

what is the others name for false solution​

Answers

Answer:

mistaken,

incorrect,

wrong,

bad,

untruthful

Answer:

Extraneous solution

Step-by-step explanation:

Extraneous solutions are solutions that come from solving a problem but are ultimately not a valid solution.

Anyone know the answer with explanation please I would appreciate it!

Answers

Answer:

[tex]\displaystyle QR = 12[/tex]

Step-by-step explanation:

First, it's never a bad idea to draw the line and see what it looks like! This is shown below (not to scale).

We are given that PS = 18 and PR = 15, and we want to determine QR.

PS is the sum of PR and RS:

[tex]\displaystyle PS = PR + RS[/tex]

Substitute:

[tex]\displaystyle (18) = (15) + RS[/tex]

Solve for RS

[tex]\displaystyle RS = 3[/tex]

Since RS ≅ PQ:

[tex]\displaystyle RS = PQ = 3[/tex]

PS is also the sum of PQ, QR, and RS. Hence:

[tex]PS = PQ + QR + RS[/tex]

Since PS = 18 and RS = PQ = 3:

[tex](18) = (3) + QR + (3)[/tex]

Solve for QR:

[tex]QR = 12[/tex]

In conclusion, QR measures 12 units.

Synthetic Substitution


(x+y)(x^2-xy+y^2)

Answers

Answer:

x^3 - y^3

Step-by-step explanation:

The sun is about 93 x 10 6 miles from earth. What’s is this distance written as a whole number

Answers

This distance would be written as a whole number as 93,000,000.

Ive been having this question for a while "what do you use first PEMDAS or Order of Operations". Well you might say it doesn't matter because a problem like this 5(3+8)=x if you use PEMDAS u first add the eight and the three and you would get eleven then you times the eleven with the five to get fifty five. So x=55. If you use Order of Operations you would multiply the three and eight by five to get 15+40=x you would add the fifteen and the forty to get fifty five making x=55. But if you took the problem {3(525/4π)}^1/3=R

then its a different situation heres the problem solved with PEMDAS.


{3(525/4π)}^1/3

{3(525/12.57)}^1/3

{3•41.77}^1/3

125.30^1/3=4.90

R=4.90


Now this is a step by step explanation on how to do order of operations.

{3(525/4π)}^1/3

(1575/12•9.40)^1/3

(1575/112.80)^1/3

13.90^1/3=2.30

R=2.30


So as you see these two equations have different answers. Now agin which of the two of them do i use Order of Operations or PEMDAS.


Please give a step by step explanation why i should use either or. All these problems were rounded to the nearest hundredth.

Answers

Answer:

Order of Operations was aught at a younger age for those just grasping the idea of multiplication and division. Exposing PEMDAS at a young age would confuse them too much, hence the order of operation groups, addition/subtraction and multiplication/division. So for the second example problem, PEMDAS would be correct because it does involve you to use parentheses as well as exponents to solve for. Very easy to mix up between order of operations and PEMDAS, but just look at it as if Order of operations is a beginner level of PEMDAS.

Step-by-step explanation:

sketch the curve of y=x² with conclusion.​

Answers

Step-by-step explanation:

I have attached pictures. Hopefully they are visible.

:)

Find the total surface area of the pyramid with base length and height be 10 cm and 12 cm respectively.​

Answers

Answer:

Hence, total surface area of the pyramid is 360 cm².

Step-by-step explanation:

We first calculate slant height L of the pyramid with base s=10 cm and height 12 cm:

L²=H²+(s/2)²=122+(10/2)²=122+5²

=144+25=169⇒

L=(169)^1/2=13

The perimeter of the base is P=4s, since it is a square, therefore, 

P=4×10=40 cm

The general formula for the lateral surface area of a regular pyramid is LSA=1/2Pl where P represents the perimeter of the base and l is the slant height.

Since the perimeter of the pyramid is P=40 cm and the slant height is l=13 cm, therefore, the lateral surface area is:

LSA=1/2Pl=1/2×40×13=260 cm²

Now, the area of the base B=s² with s=10 cm is:

B=s²=10²=100 cm²

The general formula for the total surface area of a regular pyramid is TSA=1/2Pl+B where P represents the perimeter of the base, l is the slant height and B is the area of the base.

Since LSA=1/2Pl=260 cm² and area of the base is B=100 cm², therefore, the total surface area is:

TSA=1/2Pl+B=260+100=360 cm²

Hence, total surface area of the pyramid is 360 cm².

Which decimals are equivalent to(5 x 10)+( 2 x 1/100)select all that apply.

Answers

(5 x 10) + (2 x 1/100) = 50 + 0.02 = 50.02

Water freezes at 0°C. Give two examples of two temperatures at which ice could exist.

Answers

Answer:

Ice can exist at 32°F and at -34°C since they freeze at those temperature points.

Answer:

Step-by-step explanation:

It could exist at -4oC degrees and - 8oC degrees. It could exist anywhere between 0 and - 100 . All numbers are randomly chosen. The point is that they are minus.

Which of the following sets refer to vertical angles from the diagram?

Lines and Angles

Question 29 options:

∠AOB and ∠BOC

∠BOF and ∠HOD

∠BOD and ∠HOD

∠COD and ∠HOG

Answers

Angle ∠COD and angle ∠HOG are vertically opposite angles. Then the correct option is C.

What is an angle?

The angle is the distance between the intersecting lines or surfaces. The angle is also expressed in degrees. The angle is 360 degrees for one complete spin.

Vertically opposite angle - When two lines intersect, then their opposite angles are equal.

The diagram is given below.

Angle ∠COD and angle ∠HOG are vertically opposite angles.

Hence, Angle ∠COD and angle ∠HOG are congruent.

Then the correct option is C.

More about the angled link is given below.

https://brainly.com/question/15767203

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Use the Divergence Theorem to calculate the surface integral S F · dS; that is, calculate the flux of F across S. F(x, y, z) = (x3 + y3)i + (y3 + z3)j + (z3 + x3)k, S is the sphere with center the origin and radius 3.

Answers

By the divergence theorem, the flux of [tex]\vec F[/tex] across S is equal to the volume integral of [tex]\mathrm{div}(\vec F)[/tex] over the interior of S.

We have

[tex]\vec F(x,y,z) = (x^3+y^3)\,\vec\imath + (y^3+z^3)\,\vec\jmath + (z^3+x^3)\,\vec k \\\\ \implies \mathrm{div}(\vec F) = \dfrac{\partial(x^3+y^3)}{\partial x} + \dfrac{\partial(y^3+z^3)}{\partial y} + \dfrac{\partial(z^3+x^3)}{\partial z} = 3(x^2+y^2+z^2)[/tex]

so that

[tex]\displaystyle \iint_S \vec F(x,y,z)\cdot\mathrm d\vec s = \iiint_T \mathrm{div}(\vec F)\,\mathrm dV = 3 \iiint\limits_{x^2+y^2+z^2\le3} (x^2+y^2+z^2)\,\mathrm dx\,\mathrm dy\,\mathrm dz[/tex]

To compute the volume integral, convert to spherical coordinates with

x = ρ cos(θ) sin(ϕ)

y = ρ sin(θ) sin(ϕ)

z = ρ cos(ϕ)

so that

ρ ² = x ² + y ² + z ²

dx dy dz = ρ ² sin(ϕ) dρ dϕ dθ

The region T is the interior of the sphere S, given by the set

[tex]T = \left\{(\rho,\theta,\phi) \mid 0\le\rho\le3 \text{ and } 0\le\phi\le\pi \text{ and }0\le \theta\le2\pi\right\}[/tex]

So we have

[tex]\displaystyle 3 \int_0^{2\pi} \int_0^\pi \int_0^3 \rho^4 \sin(\phi) \,\mathrm d\rho \,\mathrm d\phi \,\mathrm d\theta \\\\ = 6\pi \left(\int_0^\pi \sin(\phi)\,\mathrm d\phi\right) \left(\int_0^3 \rho^4 \,\mathrm d\rho\right) = \boxed{\frac{2916\pi}5}[/tex]

The required surface integral S, and flux across F·dS; that is [tex]\dfrac{2916\pi }{5}[/tex]

Given that,

Function;[tex]F(x, y, z) = (x^3 + y^3)\vec{i} + (y^3 + z^3)\vec{j} + (z^3 + x^3)\vec{k},[/tex]

S is the sphere with center the origin and radius 3.

We have to determine,

Use the Divergence Theorem to calculate the surface integral S, F.dS that is, calculate the flux of F across S.

According to the question,

By the divergence theorem, the flux of [tex]\vec{F}[/tex]across S is equal to the volume integral of  [tex]div(\vec{f})[/tex] over the interior of S.

S is the sphere with center the origin and radius 3.

Therefore,

[tex]F(x, y, z) = (x^3 + y^3)\vec{i} + (y^3 + z^3)\vec{j} + (z^3 + x^3)\vec{k},\\\\= div\vec({F}) = \dfrac{d(x^3+y^3)}{dx} + \dfrac{d(y^3+z^3)}{dx} + \dfrac{d(z^3+x^3)}{dx} = 3(x^{2} + y^{2} + z^{2} )\\\\Then,\\\\\int \int_S \vec{F}(x, y, z) . \vec{ds} = \int \int \int _T div\vec{F}dV= 3 \int \int\int (x^{2} + y^{2} + z^{2} )dx.dy.dz[/tex]

To compute the volume integral, convert to spherical co-ordinate,

[tex]x = p\ cos\theta\ sin\phi\\\\y = p \ sin\theta \ sin\phi\\\\z = p\ cos\phi\\\\[/tex]

Therefore,

[tex]p^2 = x^{2} + y^{2} +z^{2} \\\\dx.dy.dz = x^{2} \ sin\phi \ dp\ d\phi \ d\theta[/tex]

The region T is the interior of the sphere S is given by the set,

[tex]T = {[ p,\theta,\phi}] | \ (0\leq p\leq 3 \ and \ \ 0\leq \phi \leq \pi \ and \ 0\leq 0\leq 2\pi )[/tex]

Then,

[tex]= 3 \int^2_0 \int^\pi _0 \int^3_0 p^4. sin(\phi). dp.d\phi .d\theta\\\\= 6\pi ( \int^\pi _0 sin(\phi).d\phi) (\int^3_0 p^4dp\\\\= \dfrac{2916\pi }{5}[/tex]

Hence, The required surface integral S, F·dS; that is [tex]\dfrac{2916\pi }{5}[/tex]

To know more about Integration click the link given below.

https://brainly.com/question/13096561

Which expression does this power represent?

109


10 × 10 × 10 × 10 × 10 × 10 × 10 × 10 × 10

9 × 9 × 9 × 9 × 9 × 9 × 9 × 9 × 9 × 9

10 × 9 × 10 × 9 × 10 × 9 × 10 × 9 × 10 × 9 × 10 × 9 × 10 × 9 × 10 × 9 × 10 × 9

10 × 9

Answers

9514 1404 393

Answer:

  (a)  10 × 10 × 10 × 10 × 10 × 10 × 10 × 10 × 10

Step-by-step explanation:

You may recall that we use a multiplier to signify repeated addition:

  x + x + x = 3x

In a similar way, we use an exponent to signify repeated multiplication:

  10 × 10 × 10 = 10³

__

The exponent 9 in 10⁹ means the factor 10 appears 9 times in the product:

  10 × 10 × 10 × 10 × 10 × 10 × 10 × 10 × 10 = 10⁹

Answer:

a  10 × 10 × 10 × 10 × 10 × 10 × 10 × 10 × 10

Step-by-step explanation:

The students at a school assembly
were divided into 4 equal groups.
There were 73 students in each
group. Write and solve an equation
to determine the number of students
that were at the assembly.

Answers

Answer:

292

Step-by-step explanation:

73 students in 1 group

4 groups all together

73 Students times 4 groups = amount of students all together

so 73x4=292

Mary takes 8 days to do a full check of the
library's online catalog. Her assistant takes
12 days. If they work together, determine the
fraction of the catalog that is checked after
4 days.

Answers

Answer:

Step-by-step explanation:

[tex]\begin{array}{|c|c|c|c|c}day&1&2&3&4\\----&-----&-----&-----&-----\\Mary&\frac{1}{8} &\frac{2}{8} &\frac{3}{8} &\frac{4}{8} \\Assis&\frac{1}{12} &\frac{2}{12} &\frac{3}{12} &\frac{4}{12} \\Sum&\frac{1}{8}+\frac{1}{12}&\frac{2}{8}+\frac{2}{12}&\frac{3}{8}+\frac{3}{12}&\frac{4}{8}+\frac{4}{12}\\part&\frac{5}{24}&\frac{10}{24}&\frac{15}{24}&\frac{20}{24}=\boxed{\frac{5}{6}}\\----&-----&-----&-----&-----\\\end{array}[/tex]

The fraction of the catalog that is checked after 4 days is 5/6

If Mary takes 8 days to do a full check and her assistant takes 12 days then if they work together then the fraction of the catalog that is checked after 4 days is 1000/12.

What is fraction?

Fraction is a combination of numerator and denominator. The number above division sign is known as numerator and the number below the division sign is known as denominator. It is in p/q form in which q cannot be equal to 0.

How to find fraction?

let the catalog contains 100 things.So in this way ,

In 1 day Mary does 100/8 things completed and her assistant does 100/12 things completed in 1 day.

So in four days they will complete =100*4/8+100*4/12

=400/8+400/12

=(4800+3200)/96

=8000/96

=1000/12

Hence if Mary takes 8 days to do a full check and her assistant takes 12 days then if they work together then the fraction of the catalog that is checked after 4 days is 1000/12.

Learn more about fraction at https://brainly.com/question/78672

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A light aircraft travels 6 miles per hour less than three times the speed of a van. If the van can travel 72 miles in the same time it takes the aircraft to travel 204 miles, then what is the average speed of each?

Answers

Answer:

Van: 36 mph.

Plane: 102 mph.

Step-by-step explanation:

x = speed of van

y = common time value

(3x - 6) * y = 204 // plane

x * y = 72 // van

3xy - 6y = 204 // plane simplified

We can now substitute 72 for xy in the equation above.

3*72 - 6y = 204 --> 216 - 6y = 204

We now subtract 216 from both sides.

-6y = -12

We now divide both sides by -1 to get rid of the negative sign & then divide both sides by 6 to simplify.

y = 2

If x*y = 72, then x = 72/y = 72/2 = 36.

Thus, the speed of the van is 36 mph.

We can find the speed of the plane by using the equation from earlier, 3x - 6.

3x - 6 = 3*36 - 6 = 108 - 6 = 102.

4,582 x 10
Written in place value form

Answers

Answer:

45820

Step-by-step explanation:

the "10" means adding 1 zero to "4582" in place value

Hundred Thousand= 4

Thousand= 5

Hundred= 8

Tens= 2      

Units= 0

 

Define diameter and radius of a circle with a diagram

Answers

Answer:

Hey mate.....

Step-by-step explanation:

This is ur answer....

Radius : a straight line from the centre to the circumference of a circle or sphere.Diameter : a straight line passing from side to side through the centre of a body or figure, especially a circle or sphere.

(Diagram attached)

Hope it helps!

Brainliest pls!

Follow me! :)

the full segment of half of the circle is diameter and half segment us called radius

Three times the sum of a number and 18 is at least-30

Answers

Answer:

the sum of the number is 16 and it is al least 20 points

m-2=1.97 and explain how to do it im lowkey kind of confused on how to do this.

Answers

9514 1404 393

Answer:

  m = 3.97

Step-by-step explanation:

Your equation is written as a "one-step" linear equation.

  m -2 = 1.97

It is solved by adding 2 to both sides of the equation. (This is the "one step.")

  m -2 +2 = 1.97 +2

Simplifying gives ...

  m = 3.97

_____

If this is supposed to be an equation where -2 is a exponent, then the rules related to exponents apply. In plain text, this would be written m^-2 = 1.97.

  [tex]m^{-2}=1.97\\\\\dfrac{1}{m^2}=1.97\qquad\text{write using a positive exponent}\\\\\dfrac{1}{1.97}=m^2\qquad\text{multiply by $m^2/1.97$}\\\\\sqrt{\dfrac{1}{1.97}}=m\approx0.71247050\qquad\text{take the square root}[/tex]

g The weight of golden hamsters follows a normal distribution with a mean weight of 4.3 ounces and a standard deviation of 0.25. What is the probability that a randomly chosen hamster weighs less than 4.4 ounces

Answers

Let X be the random variable representing the weight of a hamster. Transform X to Z, which follows the standard normal distribution. We have

P(X < 4.4) = P((X - 4.3)/0.25 < (4.4 - 4.3)/0.25) = P(Z < 0.4) ≈ 0.6554

Solve quadratic equation by factoring.

Answers

Answer:

x = -5 and x = -9.

Step-by-step explanation:

To factor this, we need to find two numbers that add to 14 and multiply to 45.  These are 5 and 9.  Therefore, this equation factors to (x + 5)(x + 9) = 0.  The two x values that would make this true are -5 and -9 because they would make (x + 5) and (x + 9) equal to 0 respectively.  

While on a walk in the country, you pass a field full of horses and chickens. After a quick count, you determine there are 43 heads and 122 feet in the field. How many of each animal are there?

Answers

Horse = x = 1 head and 4 feet

Chicken =y = 1 head and 2 feet

Horse + chicken = x + y = 43 ( total heads)

Horse = 43 - y

4x + 2y = 122

4(43-y) + 2y = 122

Simplify:

172-4y + 2y = 122

Combine like terms

172-2y = 122

Subtract 172 from both sides

-2y = -50

Divide both sides by-2

Y = 25

X + y = 43

X + 25 = 43

X = 18

There are 18 horses and 25 chickens.

help is really needed...
Find the volume.
A. 240 m³
B. 351 m³
C. 214 m³
D. 356 m³

Answers

Answer:

240m^3

Step-by-step explanation:

Volume = length x width x height.

5x12x4= 240

A recipe calls for 4 cups of pecans for every 5 cups of walnuts. How many cups of pecans should be added to 8 cups of walnuts?

Answers

Answer:

5 walnuts = 4 cups of pecans

8 walnuts = 9 cups of pecans

Answer:

10 cups of pecans.

Step-by-step explanation:

The ratio between pecans and walnuts are:   [tex]\frac{4}{5}[/tex]×8

So if we make a smaller batch with 1 cup of walnuts, we will need [tex]\frac{4}{5}[/tex] cup of pecans.

So for 8 cups of walnuts, we will need [tex]\frac{4}{5}[/tex] x 8 = 6,4 cups or [tex]6 \frac{2}{5}[/tex] cups of pecans.

I'm vietanh and good luck studying!

ME has the endpoints of M(-6,4) and E (5,-2) find the midpoint and distance of ME

Answers

Answer:

(-0.5, 1)- the midpoint, the distance is sqrt157

Step-by-step explanation:

The midpont is O

x0= (-6+5)/2= -0.5

yo= (4-2)/2=1

(-0.5, 1)

The distance is sqrt ((5-(-6))^2+(-2-4)^2)=sqrt 157

Anyone who knows this mathematic question will get the brainliest

Answers

The third one is 510 not show in the pic here

Asap right now brainliest for the correct one

Answers

Answer:

Option B

Step-by-step explanation:

The next step is the result of calculating the square roots:

[tex]4^{1/2} = 2[/tex]

and

[tex]36^{1/2} = 6[/tex]

This will make the step:

2 · [tex]3^{1/2}[/tex] + 6 · [tex]3^{1/2}[/tex] = 8 · [tex]3^{1/2}[/tex]

Correct choice is B

eksponent

[tex]\sqrt[n]{x^n} = x[/tex][tex]\sqrt{x} = x^{1/2}[/tex]

[tex] = 4^{ \frac{1}{2} } .3 ^{ \frac{1}{2} } + \sqrt{36} \times 3^ \frac{1}{2} [/tex]

[tex] = \sqrt{4} \times 3 {}^{ \frac{1}{2} } + 6 \times 3 {}^{ \frac{1}{2} } [/tex]

[tex] = 2 \times 2 + 6 \times 3 {}^{ \frac{1}{2} } [/tex]

[tex] = 4 + 6 \times \sqrt{3} [/tex]

[tex] = 4 + 6 \sqrt{3} [/tex]

Could 3, 6 and 8 represent the lengths of the sides of a right triangle?
A. Yes, because the sum of the squares of the legs does equal the sum of the square of the hypotenuse.
B. No, because the sum of the square of the legs does not equal the square of the hypotenuse.
C. No, because the sum of the sides does not equal the hypotenuse.
D. Yes, because the sum of the legs does equal the hypotenuse.

Answers

Answer:

Step-by-step explanation:

No because the sum of the two shorter legs does not equal the square of the hypotenuse.

3^2 =  9

6^2 =36

8^2 =64

9 and 36 do not equal 64

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