140 : ( x - 5 ) = 7
x - 5 = 140 : 7
x - 5 = 20
x = 20 + 5
x = 25
____________________
3 x + 4 x + 9 = 72
7 x = 72 - 9
7 x = 63
x = 63 : 7
x = 9
_______________________
6 x - 15 = 3 x + 75
6 x - 3 x = 75 + 15
3 x = 90
x = 90 : 3
x = 30
_____________________
4 ( x + 5 ) = 3 ( 2 x - 6 )
4 x + 20 = 6 x - 18
6 x - 4 x = 20 + 18
2 x = 38
x = 38 : 2
x = 19
