SOLUTION: -2x+y=-15 and 2x+3y=-15

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Question 1209242: -2x+y=-15 and 2x+3y=-15
Found 2 solutions by math_tutor2020, josgarithmetic:
Answer by math_tutor2020(3817) About Me  (Show Source):
You can put this solution on YOUR website!

-2x+y = -15
2x+3y = -15

Add straight down
The x terms go away since they add to 0x or simply 0.
The y terms add to 4y
The right hand sides add to -30

4y = -30 leads to y = -30/4 = -15/2 = -7.5

Then use this value of y in either equation to find x.
-2x+y = -15
-2x-7.5 = -15
-2x = -15+7.5
-2x = -7.5
x = -7.5/(-2)
x = 3.75
x = 3 + (3/4)
x = (12/4) + (3/4)
x = (12+3)/4
x = 15/4

When stating the solution in fraction form it would be (x,y) = (15/4, -15/2)

The decimal equivalent is (x,y) = (3.75, -7.5)
Each decimal value is exact and hasn't been rounded.

I'll let the student verify this solution.

Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
system%28-2x%2By=-15%2C2x%2B3y=-15%29

Add corresponding parts.
0%2B4y=-30

y=-30%2F4=-15%2F2


Now find x.
2x-y=15
2x=y%2B15
x=%28y%2B15%29%2F2
x=%28-15%2F2%2B15%29%2F2
x=%28-15%2F2%2B30%2F2%29%2F2
%2815%2F2%29%2F2
15%2F4


x, 15%2F4
y, -15%2F2