5х+4=х-12

х-4х-20=80

350-7х=420

2(х+3)=-3(х-4)

1)5х+4=х-12 4х=-16 х=-42)х-4х-20=80 -3х=100 х=-100/3=-33 целых 1/33)350-7х=420 -7х=70 х=-104)2(х+3)=-3(х-4) 2х+6=-3х+12 5х=6 х=6/5=1,2