Question

Using identity (x+a) (x+b) =xx+(a+b) x+ab
(4x+5) (4x-1)

Answer 1

You already know the identity

$(4x + 5)(4x - 1) = (4x^{2}) +(5 - 1)4x + 5 \times ( - 1)$

$(4x + 5)(4x - 1) = 16x^{2} + 4 \times 4x + ( - 5)$

$(4x + 5)(4x - 1) = 16x^{2} + 16x - 5$

SO HERE IS YOUR ANSWER HOPE ITS HELP YOU PLEASE MARK ME AS A BRAINLIEST