SOLUTION: Solve each system by any method. x/2 - y/3 = -4 x/2 + y/9 = 0

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Question 808165: Solve each system by any method.
x/2 - y/3 = -4
x/2 + y/9 = 0

Found 2 solutions by stanbon, JBarnum:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Solve each system by any method.
x/2 - y/3 = -4
x/2 + y/9 = 0
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Modify::
3x - 2y = -24
9x + 2y = 0
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Add and solve for "x":
12x = -24
x = -2
--------
Solve for "y":
9x + 2y = 0
-18 + 2y = 0
y = 9
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Cheers,
Stan H.
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Answer by JBarnum(2146) About Me  (Show Source):
You can put this solution on YOUR website!
x%2F2+-+y%2F3+=+-4
x%2F2+%2B+y%2F9+=+0
.
Ok i hate fractions so lets change the appearance so fractions arent a sore to look at.
Find a number thats divisible by 2, 3 and 9. The easiest is to multiply all 3 together but since 9is divisible by 3 all wee need is to multiply 2 and 9 to make 18.
.
Now multiply the top and bottom line by 18
The 2s will cancel out leaving 9x/1 and the 3 will cancel out to be 6y/1 and the 9 will cancel out to be 2y/1.
.
This shows as :
9x-6y=-72
9x%2B2y=0
.
Now much easier to see how to solve id go with subtraction so x cancels out and solve for y first.
-6y-2y=-72 add like terms
-8y=-72 divide by negative eight
highlight%28y=9%29
Plug in y and solve for x
9x%2B2y=0
9x%2B2%289%29=0 multiply
9x%2B18=0 subtract 18
9x=-18 divide by 9
highlight%28x=-2%29