Question

como resolver 2^x+1 + 2^x+1 =20

Answer 1

$2^{x+1}+2^{x-1}=20\\\\2^x*2^1+2^x*2^{-1}=20\\\\2^x*(2^1+2^{-1})=20\\\\2^x*(2+\frac{1}{2})=20\\\\2^x*(\frac{4+1}{2})=20\\\\2^x*\frac{5}{2}=20\\\\2^x=20*\frac{2}{5}\\\\2^x=8\\\\2^x=2^3\\\\x=3$