Question 404460
{{{ 9^(x^2+x)=3^4}}} <==> {{{ 9^(x^2+x)=9^2}}}
<==> {{{x^2+x=2}}} ==> {{{x^2+x - 2=0}}}
==> (x+2)(x-1) = 0 ==> x = -2, 1.
Both values satisfy the original equation.