3^(3x+2)+27^(x+1) =12----------1
3^(3x+2)+3^3[^(x+1)] =12-------2
3^(3x+2)+3^(3x+3)=12-----------3
3^(3x+2) x (1+3)=12--------------4
3^(3x+2) =12/4=3=3^1----------5
3x+2=1-------------------------------6
x=-1/3---------------------------------7
I do not understand step 4 ,please explain it