Respostas

2014-07-16T14:26:06-03:00
2x - 42 = 100
2x = 100+42
2x = 142
x = 142/2
x = 71
----------
(x-8)/3 = 40
x-8 = 40*3
x = 120+8
x = 128
2014-07-16T14:30:54-03:00
Vamos lá:

2x - 42 = 100
2x = 100 + 42
2x = 142
x = 142/2
x = 71

(x - 8) :3 = 40
x - 8 = 40 . 3
x - 8 = 120
x = 120 + 8
x = 128

Abraços.