Question

Show that (5xy + 4y)² – (5xy – 4y)² = 80xy²​

Answer 1

Answer:

(25x2y2+16y2+40xy2)-(25x2y2+16y2-40xy2)

=80xy2

Answer 2

Answer:

(x+4y)(x+y)

Step-by-step explanation:

factorizing x²+5xy+4y²,

split 5xy as :

=x²+xy+4xy+4y²

=x(x+y)+4y(x+y)

=(x+y)(x+y)