Respostas

2013-11-21T21:08:29-02:00
3x+y=3      -
3x+4y=30
_________
-3y=-27
y=-27/-3
y=9

3x+y=3
3x+9=3
3x=3-9
3x=-6
x=-6/3
x=-2
3 5 3
2013-11-21T21:09:55-02:00
 \left \{ {{-3x-y=-3} \atop {+3x+4y=30}} \right.
3y = 27
y = 27/3
y = 9


3x+4y=30
3x+4.9=30
3x+36=30
3x=30 - 36
x= -6/3
x= -2
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