Question

Simplify (4m-5n)2-(4m+5n)2​

Answer 1

Answer:

We know, (a+b)2=a2+2ab+b2.

Then,

(4m+5n)2+(5m+4n)2

=[(4m)2+2(4m)(5n)+(5n)2]+[(5m)2+2(5m)(4n)+(4n)2]

=16m2+40mn+25n2+25m2+40mn+16n2

=41m2+80mn+41n2.

Therefore, option A is correct.