2^x+2^x-1+2^x-2=56 помогите

Question

2^x+2^x-1+2^x-2=56 помогите

Answer 1

2ˣ⁻²·(2²+2+1)=56
2ˣ⁻²·7=56
2ˣ⁻²=8
2ˣ⁻²=2³
x-2=3
x=5