Factor completely.
-$49 y ^ { 4 } - 81$
A) Prime
B) $\left( 7 y ^ { 2 } + 9 \right) \left( 7 y ^ { 2 } - 9 \right)$
C) $\left( 7 y ^ { 2 } - 9 \right) ^ { 2 }$
D) $\left( 7 y ^ { 2 } + 9 \right) ^ { 2 }$

Question

Quizplus · Accepted Answer

This expression is a difference of squares: $a^2 - b^2 = (a + b)(a - b)$, where $a = 7y^2$ and $b = 9$. Therefore, it factors into $(7y^2 + 9)(7y^2 - 9)$.

Factor Completely 49y4−8149 y ^ { 4 } - 8149y4−81 A) Prime B)

Factor Completely $49 y ^ { 4 } - 81$ A) Prime
B)