Factor.
-$x^{2}-4 x y-21 y^{2}$
A) $(x-7 y)(x+3 y)$
B) $(x-y)(x+3 y)$
C) $(x+7 y)(x-3 y)$
D) $(x-7 y)(x+y)$

Name: Factor. -$x^{2}-4 x y-21 y^{2}$ A) $(x-7 y)(x+3 y)$ B) $(x-y)(x+3 y)$ C) $(x+7 y)(x-3 y)$ D) $(x-7 y)(x+y)$
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Question

Quizplus · Accepted Answer

The correct factorization of $x^{2}-4 x y-21 y^{2}$ is found by looking for two numbers that multiply to $-21y^2$ and add to $-4y$. These numbers are $-7y$ and $+3y$, leading to the factorization $(x-7 y)(x+3 y)$.

Factor - x2−4xy−21y2x^{2}-4 x y-21 y^{2}x2−4xy−21y2 A) (x−7y)(x+3y)(x-7 y)(x+3 y)(x−7y)(x+3y) B) (x−y)(x+3y)(x-y)(x+3 y)(x−y)(x+3y)

Factor
- $x^{2}-4 x y-21 y^{2}$ A) $(x-7 y)(x+3 y)$ B) $(x-y)(x+3 y)$