7х+2=0 ; 8х-4=0;4х+8=0

8х=0+4
8х=4
х=1/2

4Х=-8

Х=-2

7х+2=0
7х=0-2
7х=-2
х=-2 делим на 7
х=-2/7

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