Question

4* - 5(2*) + 4 = 0, u = 2* [Note: 4* = (2*)^2
Use the substitution given

Answer 1

x = 0, 2

Explanation:

`{4}^(x) - 5( {2}^(x) ) + 4 = 0 \\ {({2}^(x))}^(2) - 5( {2}^(x) ) + 4 = 0 \\ {u}^(2) - 5u + 4 = 0 \\ (u - 1)(u - 4) = 0 \\ u = 1 \: or \: u = 4 \\ {2}^(x) = 1 \: or \: {2}^(x) = 4 = {2}^(2) \\ x = 0 \: or \: x = 2`