67-21y=25
21y=67-25
21y=42
y=42:21
y=2
83+29x=982
29x=982-83
29x=899
x=899:29
x=31
(63-y)+109=121
63-y=121-109
63-y=12
y=63-12
y=51
103-(z+47)=54
z+47=103-54
z+47=49
z=49-47
z=2
122+(y-7)=200
y-7=200-122
y-7=78
y=78+7
y=85
53-(y-13)=24
y-13=53- 24
y-13=29
y=29+13
y=42
67-21y=25
21y=67-25
21y=42
y=42:21
y=2
83+29x=982
29x=982-83
29x=899
x=899:29
x=31
(63-y)+109=121
63-y=121-109
63-y=12
y=63-12
y=51
103-(z+47)=54
z+47=103-54
z+47=49
z=49-47
z=2
122+(y-7)=200
y-7=200-122
y-7=78
y=78+7
y=85
53-(y-13)=24
y-13=53- 24
y-13=29
y=29+13
y=42