Question

booyah!

Answer 1

\[a,a ^{2},a ^{3}...\]
Multiplying first term by k(k is not zero)
\[ak, a^2,a^3...\]
The rest of the terms remain intact.
The original sum was a+a ^2+a^3..and the new sum is ak+a^2+a^3..
By what amount has the sum changed?

Answer 2

it doesnt say

Answer 3

\[\Delta S=(ak+a^2+a^3...)-(a+a^2+a^3...)=ak-a=a(k-1)\]
Delta S is the change in the sum. Did you understand?

Answer 4

yes! thank you!