(x-16)*9=126 x-16=126:9
x-16=14
x=14+16
x=30
28*(x+5)=224
x+5=224:28
x+5=8
x=8-5
x=3
(x+76):7=15
x+76=15*7
x+76=105
x=105-76
x=29
144:(x-3)=36
x-3=144:36
x-3=4
x=4+3
x=7
21*(y-8)=84
y-8=84:21
y-8=4
y=8+4
y=12
(x+67):18=4
x+67=4*18
x+67=72
x=72-67
x=5