Respostas

2013-08-07T21:49:59-03:00
X = 9 + 4
x = 13

2x - 5y = 21

2.13 - 5y = 21
26 - 5y = 21
-5y = 21 - 26
-5y = -5
y = -5/-5
y = 1
2 5 2
2013-08-07T22:00:21-03:00
X = 9+4 = 13
26-5y= 21
26-21=5y
5=5y
y =5:5 =1