SOLUTION: 2x-y=-3 x+4y=9

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Question 123840: 2x-y=-3
x+4y=9
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
1.2x-y=-3
2.x%2B4y=9
Let's use equation 2 to solve for x in terms of y, then substitute into 1.
2.x%2B4y=9
x=9-4y
1.2x-y=-3
2%289-4y%29-y=-3
18-8y-y=-3
18-9y=-3
-9y=-21
highlight%28y=21%2F9=7%2F3%29
From 2,
x=9-4y
x=9-4%287%2F3%29
x=9-28%2F3
x=27%2F3-28%2F3
x=%2827-28%29%2F3
highlight%28x=-1%2F3%29