Factor completely.
-$x^{2}+3 x y-18 y^{2}$
A) $(x-y)(x+3 y)$
B) $(x+6 y)(x-3 y)$
C) $(x-6 y)(x+y)$
D) $(x-6 y)(x+3 y)$

Question

Quizplus · Accepted Answer

The given expression can be factored by looking for two numbers that multiply to $ac$ (where $a$ is the coefficient of $x^2$ and $c$ is the constant term, here $ac = -18y^2$) and add to $b$ (the coefficient of the middle term, here $3y$). The numbers that fit this criteria are $6y$ and $-3y$, leading to the factorization $(x+6y)(x-3y)$.

Factor Completely x2+3xy−18y2x^{2}+3 x y-18 y^{2}x2+3xy−18y2 A) (x−y)(x+3y)(x-y)(x+3 y)(x−y)(x+3y) B) (x+6y)(x−3y)(x+6 y)(x-3 y)(x+6y)(x−3y)

Factor Completely $x^{2}+3 x y-18 y^{2}$ A) $(x-y)(x+3 y)$ B) $(x+6 y)(x-3 y)$