Linear Combination Problem #1

First you need to eliminate the y-variable. You do this by multipling both sides of the first equation by -2 and then add.

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

2x+6y=22

You get

-6x-6y=-30

2x+6y=22

you eliminate the y's leaving you with 4x=-8 dividing the two you get X=2

Then you sustitute the 2 for "X" in either one of these equations. I used the second one.

2x+6y=22

2(2)+6y=22

4=6y=22

y=3

Your answer is (2,3)

3x+3y=15

2x+6y=22