Multiply.
-$$\left( x ^ { 2 } + 4 y \right) \left( x ^ { 2 } - 4 y \right)$$
A) $x ^ { 4 } - 16 y ^ { 2 }$
B) $x ^ { 4 } - 8 y ^ { 2 }$
C) $x ^ { 4 } + 8 x ^ { 2 } y - 16 y ^ { 2 }$
D) $x ^ { 4 } - 8 x ^ { 2 } y - 16 y ^ { 2 }$

Question

Quizplus · Accepted Answer

This is an application of the difference of squares formula, $a^2 - b^2 = (a + b)(a - b)$, where $a = x^2$ and $b = 4y$. Thus, $(x^2 + 4y)(x^2 - 4y) = x^4 - (4y)^2 = x^4 - 16y^2$.

Multiply - (x2+4y)(x2−4y)\left( x ^ { 2 } + 4 y \right) \left( x ^ { 2 } - 4 y \right)(x2+4y)(x2−4y)

Multiply
- $\left( x ^ { 2 } + 4 y \right) \left( x ^ { 2 } - 4 y \right)$