Решить уравнение 9^x+27=28*3^x

[latex]9^x+27=28*3^x\\ 3^{2x}+27-28*3^x=0\\ 3^x=t\\ \left \{ {{t^2-28t+27=0} \atop {t\ \textgreater \ 0}} \right. \\ \left \{ {{t_1=27;t_2=1} \atop {t\ \textgreater \ 0}} \right. \\ \left \{ {{3^x=27} \atop {3^x=1}} \right. \\ \left \{ {{x=3} \atop {x=0}} \right. \\[/latex]