1)х+3=-6 2)12+х=-8 3)х-11=-7 4)100+х=0 5)12+х=-8 6)4х=3х 7)7х=4х

1)х+3=-6
х=-6-3
х=-9
-9+3=-6
-6=-6

2)12+х=-8
х=-8-12
х=-20
12-20=-8
-8=-8

3)х-11=-7
х=-7+11
х=4
4-11=-7
-7=-7

4)100+х=0
х=0-100
х=-100
100-100=0
0=0

5)12+х=-8
х=-8-12
х=-20
12-20=-8
-8=-8

6)4х=3х
4х-3х=0
х=0
4*0=3*0
0=0

7)7х=4х
7х-4х=0
3х=0
х=0/3
х=0
7*0=4*0
0=0