Question

multiply 9x^2 + 25y^2+15xy+ 12x- 20y +16 by 3x - 5y - 4 using suitable identity

Answer 1

$\: \: \: \: \: 9 {x}^{2} + 25 {y}^{2} + 15xy + 12x - 20y + 1$
is square of
3x-5y-4
so answer is
cube of 3x-5y-4