Respostas

2014-05-15T11:09:27-03:00
valor de y
15 - y = 9
-y = -15 + 9
-y = -6 .(-1)
y = 6
 
valor de x
2x - 7 = 9
2x = 7 + 9
2x = 16
x = 16/2
x = 8
2 5 2