解:原方程即:3(x-3)=5-45x-3=-40÷3x-3=-40/3x=3-40/3x=-31/3把x=-31/3代入原方程检验,5-3(-31/3-3)=5-3(-40/3)=5+40=45
3(x-3)=-40x-3=40/3x=40/3+3x=49/3
5—3(x—3)=45解方程5-3x+9=45-3x=45-14-3x=31x=-31/3
5-3x+9=45
-3(x-3)=40x-3=-40/3x=-31/3