3+4(5х-3)=4х+7 3(5х-7)-7(4х+5)=х 2(6х-5)-7(3х-5)=4х-1 -12х+4(х-3)=-8х-12
3+20х-12=4х+7 20х-4х=7-3+12 16х=16 х=1 15х-21-28х-35=х 15х-28х-х=35+21 -14х=56 х=-4 12х-10-21х+35-4х=-1 -13х=-1+10-35 -13х=-26 х=2 -12х+4х-12+8х=-12 -12=-12