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3 years ago

What is the sum of the first five terms of a geometric series with a1 =20 and r =1/4?

1 answer:

5 0

The sum of the first n terms in a geometric sequence given the first term (a1) and the common ratio (r) is calculated through the equation,

Sn = (a1(1−r^n) / (1−r)

Substituting the known terms,
Sn = (20)(1 - (1/4)^4)) / (1 - 1/4)
Sn = 26.5625

Thus, the sum of the first four terms is 26.5625.

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What's greater 9.202 or 9.209

Sav [38]

Answer:

9.209

Step-by-step explanation:

On the thousandths place, 9 is bigger than 2.

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3 years ago

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Give me 3 websites that sell legit sneakers (Jordans, Nike), for a cheap price.

grandymaker [24]

Answer:

The direct consequences of poverty are well-known — limited access to food, water, health care or education are a few examples. However, the consequences of poor living conditions on the community are seldom discussed; indeed, if members of a community suffer from poor living conditions, then the entire community suffers.

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3 years ago

If cot theta= 4/3, find csc theta

Marrrta [24]

Answer: Option d.

Step-by-step explanation:

The trigonometric identity needed is:

$csc^2\theta=cot^2\theta+1$

Knowing that $cot\theta=\frac{4}{3}$ :

Substitute it into $csc^2\theta=cot^2\theta+1$ :

$csc^2\theta=(\frac{4}{3})^2+1$

Simplify the expression:

$csc^2\theta=(\frac{4}{3})^2+1\\\\csc^2\theta=\frac{16}{9}+1\\\\csc^2\theta=\frac{25}{9}$

Solve for $csc\theta$ . Apply square root at both sides of the expression:

$\sqrt{csc^2\theta}=\±\sqrt{\frac{25}{9}}$

$csc\theta=\frac{5}{3}$

8 0

3 years ago

What is the value of a? -2(a-8)+6a=36

Aleksandr [31]

First we expand the brackets:

-2a + 8 + 6a = 36
4a + 8 = 36

We then need to get the a's onto one side and the numbers onto the other:

4a = 28

We can then divide to get an x by itself:

a = 28/4 = 7

6 0

3 years ago

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On Saturday morning, Ahmed decided to take a bike ride from one end of the 15-mile bike trail to the other end of the bike trail

frosja888 [35]

The expression which relates the total time taken and the time taken for the trip is [15s + 15(s+2)] / s² + 2s and 2.32 hours respectively.

Travel time = distance ÷ speed

Second half of the trip :

Speed = s mph

Distance covered = 15 miles

Time taken for second half of trip :

Time taken = 15 / s

First half of the trip :

Speed = s + 2 mph

Time taken for first half of trip :

Time taken = 15 / (s+2)

Total time taken :

First half + second half

15/(s+2) + 15/s = [15s + 15(s+2)] / s² + 2s

If s = 12

Substitute s = 12 into the expression :

[15(12) + 15(12+2)] / 12² + 2(12)

[180 + 210] / 144 + 24

390 / 168

= 2.32 hours

Therefore, the total time taken is 2.32 hours.

Learn more : brainly.com/question/18796573

3 0

3 years ago