OK I am really confused on how to do this...
I understand how but the numbers are not adding up
here is the problem

2x-y+4z=11
x+2y-6z=-11
3x-2y-10z=11

If the numbers are not adding up, could you please show us what you did so that someone can check your work and see where you are doing wrong?

Well, I can say that they 'add up'. Try to make all the variables in an equation the same. I mean, substitute for example x and y by their corresponding values of z. Therefore, find x in terms of z, find y in terms of z, then substitute x and y in one of the equations to solve for z. Once you have z, you can find x and y from the 'x in terms of z' you just had before, and the same thing applies to y.