caranya bagaimana matematika

4/5 (2^(3x - 2)) + 8^x /20 = 1
4/5 (1/2² . 2^3x) + 1/20 . 2^3x = 1
(4/20 + 1/20)(2^3x) = 1
5/20 . 2^3x = 1
2^3x = 20/5
2^3x = 2^2
3x = 2
x = 2/3