I need to quickly be able to solve something like this:
A + B + C = -3
6A + 3B + C = -4
8A - 4B - 2C = 22
My calculus prof set some things to zero and was able to solve it really fast that way. He didn't use matrices. I can't figure out now what he did... can anyone help?
The Attempt at a Solution
I think he was making each of the variables 0 at one point, but I tried that and it definitely didn't work, haha.