Question

if (a^3*a^5)^2=81 find a

Answer 1

(a^3×a^5)^2=9^2
a^3×a^5=9
a^8=9
a=9^1/8

Answer 2

(a^3×a^5)^2=81
(a^5+3)^2=81
(a^8)^2=9^2
a^8=9
(a^4)^2=3^2
a^4=3
4=loga3