The arithmetic sequence a_ia i ​ a, start subscript, i, end subscript is defined by the formula: a_1 = 15a 1 ​ =15a, start subscript, 1, end subscript, equals, 15 a_i = a_{i - 1} -7a i ​ =a i−1 ​ −7a, start subscript, i, end subscript, equals, a, start subscript, i, minus, 1, end subscript, minus, 7 Find the sum of the first 660660660 terms in the sequence.

Answers

Answer 1

Answer:

-1,512,390

Step-by-step explanation:

Given

a1 = 15

[tex]a_i = a_{i-1} -7[/tex]

Let us generate the first three terms of the sequence

[tex]a_2 = a_{2-1}-7\\a_2 = a_1 - 7\\a_2 = 15-7\\a_2 = 8[/tex]

For [tex]a_3[/tex]

[tex]a_3 = a_{3-1}-7\\a_3 = a_2 - 7\\a_3 = 8-7\\a_3 = 1[/tex]

Hence the first three terms ae 15, 8, 1...

This sequence forms an arithmetic progression with;

first term a = 15

common difference d = 8 - 15 = - -8 = -7

n is the number of terms = 660 (since we are looking for the sum of the first 660 terms)

Using the formula;

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

Substitute the given values;

[tex]S_{660} = \frac{660}{2}[2(15) + (660-1)(-7)]\\S_{660} = 330[30 + (659)(-7)]\\S_{660} = 330[30 -4613]\\S_{660} = 330[-4583]\\S_{660} = -1,512,390[/tex]

Hence the sum of the first 660 terms of the sequence is  -1,512,390


Related Questions

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Answer:

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Step-by-step explanation:

Find the value of x.
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Answer:

x = 18 degrees

Step-by-step explanation:

50 - 32 = 18

50-32=18°
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The correct answer for this problem is 833


When the angle of elevation of the sun is 55°, a flagpole casts a shadow that is 16.8
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Answer: 24ft (rounded)

Step-by-step explanation:

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Answer:

y=3x-1

Step-by-step explanation:

Pick any x and y point (the x and y needs to be next to each other)

I will choose (-5,-16) and (-2,-7)

Sheila is trying to run a certain number of miles by the end of the month. If Sheila is 20% of the way to achieving her goal and she has already run 4 miles, how many miles is she trying to run by the end of the month?

Answers

Answer:

I think its 20 miles after the whole month

Step-by-step explanation:

20%=4

40%=8

60%=12

80%=16

100%=20

Sheila is trying to run 20 miles by the end of the month

What is the percentage?

A percentage is a value per hundredth. Percentages can be converted into decimals and fractions by dividing the percentage value by a hundred.

Given, Sheila is trying to run a certain number of miles by the end of the month and she is 20% of the way to achieving her goal which is 4 miles.

Assuming she is trying to run x miles.

So, 20% of x miles is 4 miles.

∴ (20/100)×x = 4.

0.2x = 4.

x = 4/0.2.

x = 20 miles.

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Which value of x makes the equation 0.5(x + 16) = 3 + 0.25(x – 4) true?

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Answer:it is confusing

Step-by-step explanation:

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Answer:

The answer is 9 7/10

Step-by-step explanation:

hope this helps

F(x)=7x-3 what is the value of x when f(x)=25

Answers

Answer:

x=4

Step-by-step explanation:

7x4=28 and 28-3=25

Zhen designs a character for a video game. He draws three sizes of the character on grid paper. Zhen use the expression 6 +s2 to find the number of grid squares in a character of any size s. Find the number of grid squares in a character of size 7. Show your work.​

Answers

Answer:

Is there a grid suare you can show that comes on th e

answer if there is just edit your answer so can edit this answer if not then i and try

Step-by-step explanation:

The number of grid squares in a character of size 7 is 55.

What is the algebraic expression?

Algebraic expressions are mathematical statements with a minimum of two terms containing variables or numbers.

The expression is given in the question as:

⇒ 6 + s²  ....(i)

We can use the expression 6 + s² to find the number of grid squares in a character of size s.

As per the given question, we are looking for the number of grid squares in a character of size 7.

Substitute the value of s = 7 in the expression gives us :

⇒ 6 + 7²

⇒ 6 + 49

⇒  55

Therefore, the number of grid squares in a character of size 7 is 55.

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What is the y and x-intercept of the equation below?

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Answers

Answer:

2 on the y axis and 6 on the x axis

Step-by-step explanation:

Answer:

x intercept : (6,0)

y intercept : (0,2)

Step-by-step explanation:

Which relation represents a function?

A: {(5, -9), (3, -11), (0, -13), (5, -15)}

B: {(-4, -13), (-1, -7), (2, -1), (2,5), (6, 7)}

C:{(-8.1, 2), (-7.6, 2), (-7.1, 2), (-6.6, 2)}

D: {(-1, ), (-1, 1), (1, 2), (1, 4), (3, 8)}​

Answers

C represents a function.
A function cannot have two or more inputs with different outputs
“C” represent a function
The point of a function is that the x axis(the first number) doesn’t repeat a number meaning c is the answer

Kevin gave 5/12 of his candy bar to Emily and 1/2 of his candy bar to David. How much of the candy bar does Kevin have left for himself? Your answer should be in the form of a simplified fraction. *

Answers

Answer:

[tex]Fraction\ Left = \frac{1}{12}[/tex]

Step-by-step explanation:

Given

[tex]Emily = \frac{5}{12}[/tex]

[tex]David = \frac{1}{2}[/tex]

Required

Determine the fraction left

The whole candy will be represented with 1:

So:

[tex]Emily + David + Fraction\ Left = 1[/tex]

This gives:

[tex]\frac{5}{12} + \frac{1}{2} + Fraction\ Left = 1[/tex]

Collect Like Terms

[tex]Fraction\ Left = 1 -\frac{5}{12} - \frac{1}{2}[/tex]

Take LCM

[tex]Fraction\ Left = \frac{12 - 5 - 6}{12}[/tex]

[tex]Fraction\ Left = \frac{1}{12}[/tex]

Hence, the fraction left is 1/12

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Answers

Answer: pretty sure it's c: 908cm

Step-by-step explanation:

454÷25= 18.16 and 18.16÷0.5= 908

Here we need to perform a change of units, from real distances to distances in a map.

We will find that the distance on the map is 9.08cm

Let's see how to get that.

First, the information that we have is:

Each 0.5 cm in the map represent 25 kmLondon is 454 km away from Paris.

The first thing we need to find is how many times we have 25km in 454km, we will get:

n =  454km/25km = 18.16

Each one of these 18.16, is represented with 0.5cm in the map, then the distance in the map is:

distance = 18.16*0.5 cm = 9.08cm

The distance on the map is 9.08cm

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Answers

Answer:

75/5=15

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Step-by-step explanation:

Answer:

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Step-by-step explanation:

Sallys Unit Rate is 15 dollars an hour

Andreas Unit Rate is 16 dollars an hour

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Answers

Answer:

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Step-by-step explanation:

By using Distributive Property we distribute 6 by multiplying both x and 7 by 6

(6*x)+(6*7)

6x+42

Answer:

6x+42

Step-by-step explanation:

if you multiply a number in this case 6 by a pharenthesis you have to multiply that number by each term inside the pharenthesis.

6(x+7) is 6*x +6*7 = 6x+42

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Answers

Answer:

P = 42.84  cm

Step-by-step explanation:

A half-circle is joined to an equilateral triangle with side lengths of 12 units.

We need to find the perimeter of the resulting shape.

The perimeter of the half cirle is πr.

The diameter of the circle is 12. It means radius is 6 units.

An equilateral triangle has 3 equal sides. So, perimeter of the triangle is given by :

P = πr  + 12 +12

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Hence, the perimeter of the resulting shape is 42.84  cm.

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Step-by-step explanation:

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Answers

Answer:

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Step-by-step explanation:

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Answers

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Answer:

no solution

Step-by-step explanation:

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Answers

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Answers

Answer:

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Step-by-step explanation:

The greatest common factor of f and g is 1.

What is the greatest common factor?

The greatest number can divide the numbers into equal parts.

It is called the greatest common factor.

Given:

2 prime numbers are represented by f and g.

That means the numbers are only factored by 1 and the number itself.

Let f = 2 and g = 3

Here, 2 and 3 are the prime numbers.

The GCF of 2 and 3 is 1.

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Answers

Answer:

You should try it it is sooo easy

Step-by-step explanation:

Which of the following are solutions to the equation below?
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Answers

Answer:

A.2

Step-by-step explanation:

X is equal to 2

If you plug in 2 for X both sides will equal each-other

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Answer:

-5 and 2

Step-by-step explanation:

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Answers

Answer:

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Step-by-step explanation:

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Answers

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Answers

Answer:

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Step-by-step explanation:

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Answers

The least common multiple of 6 and 21 is 42.

Answer:

LCM : 42

Step-by-step explanation:

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Answer:

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Step-by-step explanation:

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The last one is the answer.......

Answer:

D. 7 up and 5 left

Step-by-step explanation

Pick any letter and see how you can get it to match the same letter but on the other shape. Ex. letter A if you go up 7 and then go 5 to the left it will be at the exact spot as A'. Hope this helps

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