Respostas

2014-03-15T16:19:21-03:00
2b - 4 = 16
2b = 20
b = 10

3a + 2 = a + 6
3a - a = 6 - 2
2a = 4
a = 2

2d = 8
d = 4

5 + c = 4
c = -1
1 5 1