Question

(-7x-2y)2 expand it by suitable identity

Answer 1

(-7x×2)-(2y×2) by distributing property

Answer 2

$\text {Using the algebraic formula : } (a + b)^2 = a^2 + 2ab + b^2$

$(-7x-2y)^2 = (-7x)^2 + 2(-7x)(-2y) + (-2y)^2 = 49x^2 + 28xy + 4y^2$