SOLUTION: I need help please with this graphing problem by solving each system by addition x-2y=-1 -x+5y=9

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Question 178966: I need help please with this graphing problem by solving each system by addition
x-2y=-1
-x+5y=9

Answer by Mathtut(3670) About Me  (Show Source):
You can put this solution on YOUR website!
x-2y=-1.....eq 1
-x+5y=9.....eq 2
:
what you doing here is adding all the terms from eq1 to all the terms in eq 2
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we can only put together like terms so x-x=0...so the x term is eliminated
:
-2y+5y=3y
-1+9=8
:
so we are left with 3y=8
:
3y=8
:
highlight%28y=8%2F3%29divided by 3 to isolate the variable y
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now take y's found value and plug it back into either numbered equation
I choose eq 1
:
x-2(8/3)=-1
:
x-16/3=-1
:
3x-16=-3.....multiplied all terms by 3
:
3x=13
:
highlight%28x=13%2F3%29