Question

5^(x +1)-3*5^(x-2)=122

Answer 1

$5^{x+1}-3*5^{x-2}=122\5^x*5-3*5^x*5^{-2}=122\5^x=t\5t-frac{3t}{25}=122\125t-3t=3050\122t=3050\t=25\5^x=25\5^x=5^2\x=2$