Question 1071215
Written poorly, maybe:  3^7x=81^x+9
?


This would be unambiguous and more easily solvable:
3^(7x)=81^(x+9)


to appear, {{{3^(7x)=81^(x+9)}}}.

-
{{{3^(7x)=(3^4)^(x+9)}}}


{{{3^(7x)=3^(4(x+9))}}}


{{{3^(7x)=3^(4x+36)}}}


The exponents would be equal.
{{{7x=4x+36}}}
{{{3x=36}}}
{{{highlight_green(x=12)}}}