Use substitution to factor the polynomial completely.
-$8 x ^ { 4 } - 6 x ^ { 2 } - 9$
A) $\left( 2 x ^ { 2 } - 3 \right) \left( 4 x ^ { 2 } + 3 \right)$
B) $\left( 2 x ^ { 2 } + 1 \right) \left( 4 x ^ { 2 } - 9 \right)$
C) $( 4 x - 3 ) ( 2 x + 3 )$
D) $\left( 8 x ^ { 2 } - 3 \right) \left( x ^ { 2 } + 3 \right)$

Question

Quizplus · Accepted Answer

By substituting $y = x^2$, the polynomial becomes $8y^2 - 6y - 9$, which factors as $(2y - 3)(4y + 3)$. Substituting back $x^2$ for $y$, we get $(2x^2 - 3)(4x^2 + 3)$.

Use Substitution to Factor the Polynomial Completely 8x4−6x2−98 x ^ { 4 } - 6 x ^ { 2 } - 98x4−6x2−9

Use Substitution to Factor the Polynomial Completely $8 x ^ { 4 } - 6 x ^ { 2 } - 9$