Question

Помогите решить позжалуйста

Answer 1

1) 2^х - 2^(х-2) - 3 = 0
a = 2^x
a - (a/(2^2)) - 3 = 0
а - а/4 - 3 = 0
3а/4 = 3
3а = 12
а = 4
2^x = 4
x = 2

2) 2^(3x) - 2^4 = 0
3x - 4 = 0
3x = 4
x = 4/3

3) 3^x = 1/81
3^x = 3^(-4)
x = -4