systems of linear equations - driving myself crazy

[jenlspooner]

This is my very first post. I'm desperate to figure out the answer to this system of linear equations that I've been working on for an hour, and feel really stupid...

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

I've tried both the substitution method, which is very cumbersome with such complicated equations, and the elimination method. I think the elimination method would work better, but I keep getting different answers each time. Can someone please help me?

Thank you soooo much in advance.

 

[jenlspooner]

Do you understand that your equations are (simplified):
6x - y = 6 [1]
6x + 7y = -18
????

I did get the second one before, but not the first one...

So If I subtract [2] from [1] I get y=-3. Then after I plugged in -3 into [1] I got x=1/2

I was messing up the subtraction of negative numbers. Thanks for your help!!