Question 173574
Rule:  {{{x^m*x^n=x^(m+n)}}}


Apply the rule:  {{{3^(x+2)+3^x=270=3^x*3^2+3^x=270}}}


Factor the left:  {{{(3^x)(3^2+1)=270}}} → {{{3^x*10=270}}} → {{{3^x=27}}}


But {{{3^3=27}}} therefore {{{x=3}}}