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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Jan is 2/3 of Karyn's age. Jan's age 8 years ago is 2/5 of Katyn's age 4 yeats from now. Jan is how many younger than Karyn?

Elden [556K]

Answer:

12 years younger.

Step-by-step explanation:

Let Jan's age be J and Karyn's age be K.

$J= \frac{2}{3} K$

Jan's age 8 years ago is 2/5 of Karyn's age 4 yeaRs from now.

$J-8 = \frac{2}{5} (K+4)$

=> $(\frac{2}{3} - \frac{2}{5} ) K = \frac{8}{5} + 8$

=> 4K = 48 X 3

=> K= 36.

=> J= 24.

So Jan is 12 years younger.

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3 years ago

Maurice walked 6 miles in 132 minutes. Monica walked 4.5 miles in 90 minutes. is the ratio of miles walked to minutes the same f

expeople1 [14]

No its not the same.
Maurice walked 1 mile in 22 mins
Monica walked 1 mile in 20 mins

3 0

3 years ago

Please help I'm confused. It's finding a function

shepuryov [24]

Easy, that is the slope from (2,f(2)) to (3,f(3))

remember that the slope between the points (x1,y1) and (x2,y2) is
(y2-y1)/(x2-x1)

find f(2) and f(3)
f(2)=2²+6(2)+5=4+12+5=21
f(3)=3²+6(3)+5=9+18+5=32

so the slope from (2,21) to (3,32) is (32-21)/(3-2)=11/1=11

answer is 11

3 0

4 years ago

P divided by 8.2 = 9.3 who is smart

Svet_ta [14]

P=1886/25 or 75 11/25

Hope this helps :)

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2 years ago

Read 2 more answers

Solve IzI > ( ½) a. b. c.

andrey2020 [161]

Answer: it is the third one hope it helps

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3 years ago