If you mean factor, that equation factors to (x+6)(x-1). If C, in the form X^2+Bx+C, is negative, then the signs of your factors are going to be opposite, like (x+ )(x- ). If C is positive, then the sign of your factors are going to be the sign of B, in AX^2+BX+C. So, if you have (this is just random, may not be factorable) 3x^2-5x+3, you're going to have something like (x- )(x- )
Find what 2 numbers multiply to -6 and add to 5. I got -1 and 6. Write your answer like this: (x-1)(x+6) =0. Use the zero product property and get 2 solutions of 1 and -6 for x.