Put them one ender each other like this:
Code:
3x + 7y = -1
2x + 3y = 6
Now, you have to eliminate one of the terms, either x or y.
I'll show you how to eliminate x.
If you multiply everything in the first equation by 2 and the second equation by three, you get 6x + 14y = -2 and 6x + 9y = 18 respectively.
Now, put back one under the other:
Code:
6x + 14y = -2
6x + 9y = 18
See what I did? Now, x has the same coefficient (the number in front of x). Now, you can subtract the second equation from the first like an ordinary subtraction:
Code:
6x + 14y = -2 -
6x + 9y = 18
0x + 5y = -20
Then, you have only one variable, which you can find the value.
Lastly, use that value of y in any of the two previous equations to find the value of x and you're done! :)
I hope it helped! :)