SOLUTION: how do i solve 9x-2y=3 3x-y=6 using substitution

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Question 769999: how do i solve
9x-2y=3
3x-y=6
using substitution
Answer by kmadison(20) About Me  (Show Source):
You can put this solution on YOUR website!
so 1st lets solve the 2nd equation for y:
-y+=+6+-+3x
y+=+3x+-+6
now we plug in for y in the 1st equation:
9x+-+2%283x+-+6%29+=+3
now we solve for x:
1st: Rewrite the expression: 9x+-+6x+%2B+12+=+3
2nd: Combine like terms: 3x+=+-9
x+=+-3
now going back to the 1st expression we can plug in -3 for x:
y+=+3%28-3%29+-+6
y+=+-15
so our final result is (-3, -15) which we can verify in both expressions:
9%28-3%29+-+2%28-15%29+=+3
and
3%28-3%29+-+%28-15%29+=+6