Question

3^2x +3^x -2 = ?

Answer 1

let u=3^x, then you have u^2+u-2=0 which you can solve by factoring

(u+2)(u-1)=0
u=-2 or u=1

now sub back to x:

3^x=-2
no solution since 3^x>0 always
or
3^x=1
x=0

solution set {0}