Question 1002689
{{{3^(x+1)*9^(-x)=27}}}


{{{3^(x+1)*(3^2)^(-x)=27}}}


{{{3^(x+1)*3^(2(-x))=27}}}


{{{3^(x+1)*3^(-2x)=27}}}


{{{3^(x+1-2x)=3^3}}}


{{{3^(1-x)=3^3}}}

The bases are equal, both being 3.  The exponents must also be equal.


{{{1-x=3}}}
{{{-x=3-1}}}
{{{x=1-3}}}
{{{highlight(x=-2)}}}