如题所述
4x-3(20-x)=5x-7(20-x)
4x-3(20-x)=5x-7(20-x)解:4x-60+3x=5x-140+7x 4x+3x-5x-7x=-140+60 -5x=-80 x=161-2x-5/6=3-x/412-2(2x-5)=3(3-x)12-4x+10=9-3xx=13 x/0.3-0.17-0.2x/0.02=1 10x/3-(17-20x)/2=120x-3*(17-20x)=620x-51+60x=680x=57x=57/80