Question

(b) Simplify: (5x + 4y)2 - (5x - 4y)2 - 70xy​

Answer 1

Answer:

5x+4y)(2)−(5x−4y)(2)−70xy

Distribute:

=(5x)(2)+(4y)(2)+−10x+8y+−70xy

=10x+8y+−10x+8y+−70xy

Combine Like Terms:

=10x+8y+−10x+8y+−70xy

=(−70xy)+(10x+−10x)+(8y+8y)

=−70xy+16y

Answer 2

Answer:

16y-70xy

Step-by-step explanation:

(5x+4y)2-(5x-4y)2-70xy = (10x+8y) -(10x-8y) -70xy

                                       =10x+8y-10x+8y-70xy

                                       =16y-70xy