Question

Define an infinite geometric series.

Answer 1

2(5) = 2 * 1/(1-x) seems useable

Answer 2

a/(1-r) = Sum
First value (a) is 2 and Sum is 10.
2/(1-r) = 10
2 = 10(1-r)
1/5 = 1-r
r = 4/5

So first four terms are
a1 = 2
a2 = 2 * 4/5 = 8/5
a3 = 8/5 * 4/5 = 32/25
a4 = 32/25 * 4/5 = 128/225

Answer 3

Thank you so much both of you (:!

Answer 4

The last one should be 128/125, sorry

Answer 5

Okay; I really appreciate your help!