Question

已知2的x+3次方-2的x+1次方=192,求x的值

Answer 1

2^(x+3)-2^(x+1)
=2^(x+1)·(2^2-1)
=2^(x+1)·3=192
∴2^(x+1)=64
∴x+1=6,x=5