[MOVED] System of linear equations w/ X & Y

[Endis5]

I was doing great on solving system equations until I was thrown one with two variables on both sides. Can someone get me on the right track please. I've tried several different ways to solve this and can't figure it out. I know the correct answers but don't know how to get them (I need to understand the process).

15x - 18 - 2y = -3x + y
10x + 7y + 20 = 4x - 12

answer x = 1/2
y = -3

Thanks in advance!
Sandy

 

[skeeter]

all you have to do is "clean up" each equation a little by getting both variables on one side ...

15x - 18 - 2y = -3x + y
18x - 3y = 18
6x - y = 6

10x + 7y + 20 = 4x - 12
6x + 7y = -32

now you have the system ...
6x - y = 6
6x + 7y = -32

but, the solution to this system is not what you cited ...

6x + 7y = -32
-6x + y = -6
----------------
8y = -38
y = -19/4

6x + (19/4) = 6
24x + 19 = 24
24x = 5
x = 5/24

Recheck your original equations.

 

[Endis5]

Thank you! I posted the problem wrong, thus the wrong answer but this example is all I needed. I can see where I was going wrong.

Thanks for the help.
Sandy