Question 2(iv) Use the identity (x+a)(x+b)=x2+(a+b)x+ab to find the following products: (4x+5)(4x−1)
(4x+5)(4x−1)=(4x)2+(5−1)×4x+5×(−1) =16x2+(5−1)×4x−5 [Using identity (x+a)(x+b)=x2+(a+b)x+ab] =16x2+4×4x−5 =16x2+16x−5