Question

Find the sum of the first 10 terms of the geometric sequence. NO LINKS!!!!

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Answer 1

9514 1404 393

Answer:

9. about 5.785712587

10. 1023

Explanation:

The sum of n terms of a geometric series with first term a₁ and common ratio r is given by ...

`S_n=a_1*(r^n-1)/(r-1)`

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9. a₁ = 9/2, r = 2/9

`S_(10)=(9)/(2)\cdot(1-(2/9)^(10))/(1-(2/9))=(498111911)/(86093442)\approx5.785712587`

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10. a₁ = -3, r = -2

`S_(10)=-3\cdot((-2)^(10)-1)/(-2-1)=1023`