Question

If in a G.P, a3 +a5 =90 and r = 2 ,then the first term is

Answer 1

Answer:

$a3 + a5 = 90 \\ a ({r}^{2} + {r}^{4} ) = 90 \\ a(4 + 16) = 90 \\ a = \frac{90}{20} \\ a = 4.5$