If 9^a = 25 then 3^a =?

Question

If
9+11-2=153
13+14-1=223
then
12+25-3=??
explain step by step.

1) 811
2) 700
3) 686
4) 205

Answer 1

If 9^a = 25 then 3^a =?

Take square root both side

(9^a)^1/2 = (25)^1/2
(3)^2*a/2=(5)^2*1/2
3^a=5

Answer 2

9^a = 3^(2a) = 25.
3^(2a/2) = 3^a = 25^(1/2) = 5.