Respostas

2013-06-21T17:40:04-03:00

x=5-2y
2(5-2y)+y=3
10-4y+y=3
-3y=-7(-1)
y=7/3
x=5-14/3=15-14=1/3
a/3+7b/3=2
b/3-7a/3=4
a+7b=6
b-7a=12
a=6-7b
b-7(6-7b)=12
.olha ai acho q ta certo

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