Question

The sum of an infinite GS is 15 and the sum of their square is 45, then the common ratio is:
a)3/4
b)1/4
c)2/3
d)5/6

Answer 1

solve these
\[ 15 = \frac{a}{1 - r}\]

\[ 45 = \frac{a^2}{1 - r^2}\]

Answer 2

Thank you..