7х+2=0 ; 8х-4=0;4х+8=0
7х+2=0 7х=0-2 7х=-2 х=-2 делим на 7 х=-2/7
8х=0+4 8х=4 х=1/2
4Х=-8
Х=-2
7х+2=0 7х=0-2 7х=-2 х=7: (-2) х= -3.5 8х-4=0 8х=0+4 8х=4 х=8: 4 х= 2 4х+8=0 4х=0-8 4х=-8 х=4: (-8) х= -0.5