Factor.
-$x ^ { 2 } - 3 x y - 10 y ^ { 2 }$
A) $( x - y ) ( x + 2 y )$
B) $( x + 5 y ) ( x - 2 y )$
C) $( x - 5 y ) ( x + y )$
D) $( x - 5 y ) ( x + 2 y )$

Question

Quizplus · Accepted Answer

The correct factorization is found by looking for two numbers that multiply to $ac$ (where $a$ is the coefficient of $x^2$ and $c$ is the constant term, here $ac = -10y^2$) and add to $b$ (the coefficient of $x$, here $-3y$). The numbers -5y and 2y work, leading to the factorization $(x - 5y)(x + 2y)$.

Factor - x2−3xy−10y2x ^ { 2 } - 3 x y - 10 y ^ { 2 }x2−3xy−10y2

Factor
- $x ^ { 2 } - 3 x y - 10 y ^ { 2 }$