Question

Expand using formula
(4x + 2y + 3)(4x + 2y – 3)​

Answer 1

Answer:

(4x+2y+3)(4x+2y-3)

let 4x+2y= a

then,

(a+3)(a-3)

=a^2-3^2

=a^2-9

=(4x+2y)^2-9

=(4x)^2+2.4x.2y+(2y)^2-9

=16x^2+16xy+4y^2-9