Question

2^x+3  +  2^x+1  +  2^x   =88

Answer 1

$2^{x+3}+2^{x+1}+2^{x}=88\\2^{x}.2^{3}+2^{x}.2^{1}+2^{x}=88$

Colocando 2^x em evidência:

$2^{x}(2^{3}+2^{1}+1)=88\\2^{x}(8+2+1)=88\\2^{x}(11)=88\\2^{x}=88/11\\2^{x}=8\\2^{x}=2^{3}\\x=3$