SOLUTION: Determine whether each sysem is consistent or inconsistent by solving it algebraically and graphically. I am having a problem solving fory "y". They say the answer is 9/4 or 2.2

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Question 320147: Determine whether each sysem is consistent or inconsistent by solving it algebraically and graphically.
I am having a problem solving fory "y". They say the answer is 9/4 or 2.25
2x-y=1
4x+2y=7
2(2x) - (2y = -1(2)
4x-2y=-2 2(5/8)-y= 1
4x+2y=7 5/4-1=y
8x = 5
x=5/8
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
2x-y=1 ___ multiplying by 2 ___ 4x - 2y = 2
4x+2y=7

adding equations to eliminate y's ___ (4x - 2y) + (4x + 2y) = 2 + 7 ___ 8x = 9 ___ x = 9/8

substituting to find y ___ 2(9/8) - y = 1 ___ (9/4) - 1 = y ___ 5/4 = y