Factor by grouping.
-$12 x ^ { 4 } - 15 x ^ { 2 } - 8 x ^ { 2 } + 10$
A) $\left( 3 x ^ { 4 } - 2 \right) ( 4 x - 5 )$
B) $\left( 3 x ^ { 2 } - 2 \right) \left( 4 x ^ { 2 } - 5 \right)$
C) $\left( 3 x ^ { 2 } + 2 \right) \left( 4 x ^ { 2 } + 5 \right)$
D) $\left( 12 x ^ { 2 } + 2 \right) \left( x ^ { 2 } + 5 \right)$

Question

Quizplus · Accepted Answer

We can group the first two and last two terms:

\begin{align*}
12 x ^ { 4 } - 15 x ^ { 2 } - 8 x ^ { 2 } + 10 &= \left(12 x ^ { 4 } - 8 x ^ { 2 } ight) - \left(15 x^2 - 10 ight) \
&= 4x^2(3x^2-2) - 5(3x^2-2) \
&= \boxed{\left(3x^2 - 2ight)\left(4x^2 - 5ight)}
\end{align*}

Factor by Grouping 12x4−15x2−8x2+1012 x ^ { 4 } - 15 x ^ { 2 } - 8 x ^ { 2 } + 1012x4−15x2−8x2+10

Factor by Grouping $12 x ^ { 4 } - 15 x ^ { 2 } - 8 x ^ { 2 } + 10$