Multiply.
-$$[ ( 4 x - 4 ) + 7 y ] [ ( 4 x - 4 ) - 7 y ]$$
A) $16 x ^ { 2 } - 32 x + 16 + 49 y ^ { 2 }$
B) $16 x ^ { 2 } + 32 x + 16 - 49 y ^ { 2 }$
C) $16 x ^ { 2 } - 32 x + 16 - 49 y ^ { 2 }$
D) $16 x ^ { 2 } - 32 x + 16 + 56 x y - 56 y + 49 y ^ { 2 }$

Question

Quizplus · Accepted Answer

This problem uses the difference of squares formula, $(a+b)(a-b) = a^2 - b^2$. Here, $a = 4x - 4$ and $b = 7y$, so the expression simplifies to $(4x - 4)^2 - (7y)^2 = 16x^2 - 32x + 16 - 49y^2$.

Multiply - [(4x−4)+7y][(4x−4)−7y][ ( 4 x - 4 ) + 7 y ] [ ( 4 x - 4 ) - 7 y ][(4x−4)+7y][(4x−4)−7y]

Multiply
- $[ ( 4 x - 4 ) + 7 y ] [ ( 4 x - 4 ) - 7 y ]$