2^2x-5*6^x+3*3^2x=0
2^2x-5*2^x*3^x+3*3^2x=0
Делим на 3^2x <> 0
(2/3)^2x - 5*(2/3)^x + 3 = 0
замена (2/3)^x = t > 0
t^2 - 5t + 3 = 0
D= 25 - 12 = 13
t12 = (5 +- √13)/2
1. (2/3)^x = (5 - √13)/2
x = 3/2 log(2/3) (5 - √13)/2
2. (2/3)^x = (5 + √13)/2
x = 3/2 log(2/3) (5 + √13)/2