9514 1404 393
Answer:
9. about 5.785712587
10. 1023
Step-by-step explanation:
The sum of n terms of a geometric series with first term a₁ and common ratio r is given by ...
[tex]S_n=a_1\times\dfrac{r^n-1}{r-1}[/tex]
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9. a₁ = 9/2, r = 2/9
[tex]S_{10}=\dfrac{9}{2}\cdot\dfrac{1-(2/9)^{10}}{1-(2/9)}=\dfrac{498111911}{86093442}\approx5.785712587[/tex]
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10. a₁ = -3, r = -2
[tex]S_{10}=-3\cdot\dfrac{(-2)^{10}-1}{-2-1}=1023[/tex]
