SOLUTION: use either substitution or the addition-subtraction method to solve. 4x+6y=9 3x-6y=12 here's what i did to get my answer: 9-4x=3x-12 7x=21 x=3

Question 878850: use either substitution or the addition-subtraction method to solve.
4x+6y=9
3x-6y=12
here's what i did to get my answer:
9-4x=3x-12
7x=21
x=3

4(3)+6Y=9
12+6Y=9
6Y=-3
Y=-1/2
can someone show me how to check my answer?

Answer by josgarithmetic(39618) (Show Source): You can put this solution on YOUR website!
I cannot find any justification for your two first steps. Do you see that the two given equations are perfectly set for using the Elimination Method? Sum the two left members and equate with the sum of the two right members. This will eliminate the 6y, and you can quickly solve for x.
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