Find an expression which represents the difference when (-4x-5)(−4x−5) is subtracted from (10x-5)(10x−5) in simplest terms.

Answer 1

(10x-5)(10x−5) - (-4x-5)(−4x−5)
= 100x^2 - 100x + 25 - 16x^2 - 40x - 25
= 84x^2 - 140x

Answer 2

assuming the usual copy/paste numeric duplication,
(10x−5) - (-4x-5) = 10x-5+4x+5 = 14x