Multiply.
-$\left( \frac { 4 } { 7 } y - 10 \right) \left( \frac { 4 } { 7 } y + 10 \right)$
A) $\frac { 16 } { 49 } y ^ { 2 } - 20$
B) $\frac { 16 } { 49 } y ^ { 2 } - \frac { 80 } { 7 } y - 100$
C) $\frac { 16 } { 49 } y ^ { 2 } + \frac { 80 } { 7 } y - 100$
D) $\frac { 16 } { 49 } y ^ { 2 } - 100$

Question

Quizplus · Accepted Answer

This is a difference of squares problem, which follows the formula $a^2 - b^2 = (a - b)(a + b)$. Here, $a = \frac{4}{7}y$ and $b = 10$, so the product is $\left(\frac{4}{7}y\right)^2 - (10)^2 = \frac{16}{49}y^2 - 100$.

Multiply - (47y−10)(47y+10)\left( \frac { 4 } { 7 } y - 10 \right) \left( \frac { 4 } { 7 } y + 10 \right)(74​y−10)(74​y+10)

Multiply
- $\left( \frac { 4 } { 7 } y - 10 \right) \left( \frac { 4 } { 7 } y + 10 \right)$