The answer is

You multiply the x to the x.
Then you multiply the x to the ones, and the x to the negative ones. You combine the -1x to 1x to get -4x, because -6+2 is -4.
Lastly you multiply the negative ones to the ones, and combine like terms to get -12.
Since the quadratic form is

, you plug in a, b, and c with 1. -4, and -12, so it looks like this:
