SOLUTION: solve the system by addition 2x - 9y = -4 x - 4y = -1

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Question 89529: solve the system by addition
2x - 9y = -4
x - 4y = -1
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
multiply the second equation by -2 to get -2x+8y=2 ... add this result to the first equation to get

(2x-9y)+(-2x+8y)=-4+2 ... -y=-2 ... y=2 ... x-4(2)=-1 ... x=7