Question

2^(x+1)+2^x-1)+2^x=28

Answer 1

Решение. 2^x+1 +2^x-1 +2^x = 28; 2^(x)=y; 2*y+0,5*y+y=28; 3,5*y=28; y=8; 2^x=8; x=3.