Respostas

2014-08-22T23:16:57-03:00
20x -30 = 40 +30x -20
20x -30x = 40 -20 +30
-10x = 20 +30
-10x= 50 . (-1)
10x= -50
x=  \frac{-50}{10}
x=-5

2014-08-22T23:19:50-03:00
Olá!


20x - 30 = 40 + 30x - 20
20x - 30x = 40 - 20 + 30
- 10x = 50
10x = - 50
x = - 5

Espero que tenha ajudado!