a ) 6x - 36 = 144 : 2
6x - 36 = 72
6x = 72 + 36
6x = 108
x = 108 : 6
x = 18
b ) ( 42 - x ) - 21 = 15
42 - x = 15 + 21
42 - x = 36
x = 42 - 36
x = 6
a,6x-36=144:2 b,(42-x)-21=15
6x-36=72 42-x=15+21
6x=72+36 42-x=36
6x=108 x=42-36
x=108:6 x=6
x=18
a,6x-36=144:2 b,(42-X)-21=15
6x-36=72 42-X=15+21
6x=72+36 42-X=36
6x=108 X=42-36
x=108:6 X=6
x=18