Question

Solve 2^3-x = 5^2x+1

Give an exact solution.

Answer 1

do you mean

2^(3-x) = 5^(2x+1) ??????

Answer 2

if so then
(3x-1) ln 2 = (2x+1) ln 5

3 x ln 2 - 2 x ln 5 = ln 5 + ln 2

x (ln 8 - ln 25) = ln 10

x ln (8/25) = ln 10

x = ln 10 / ln (8/25)