12x=60
x=60/12
х=5
51z=357
z=357/51
z=7
33y=132
y=132/33
у=4
2x-15=13
2x=13+15
2x=28
x=28/2
х=14
7y-25=45
7y=45+25
7y=70
y=70/7
у=10
30-4x=70
-4x=70-30
-4x=40
x=40/-4
х=-10
49-3x=34
-3x=34-49
-3x=-15
x=-15/-3
9y-89=55
9y=55+89
9y=144
y=144/9
у=16
74-8z=2
-8z=2-74
-8z=-72
z=-72/-8
z=9
12x=60
x=60/12
х=5
51z=357
z=357/51
z=7
33y=132
y=132/33
у=4
2x-15=13
2x=13+15
2x=28
x=28/2
х=14
7y-25=45
7y=45+25
7y=70
y=70/7
у=10
30-4x=70
-4x=70-30
-4x=40
x=40/-4
х=-10
49-3x=34
-3x=34-49
-3x=-15
x=-15/-3
х=5
9y-89=55
9y=55+89
9y=144
y=144/9
у=16
74-8z=2
-8z=2-74
-8z=-72
z=-72/-8
z=9