b) 2x^2y + 4xy^2 + 2y^3 – 8y.
b) 2x2y + 4xy2 + 2y3 – 8y.
b) 2x2y + 4xy2 + 2y3 – 8y
= 2y(x2 + 2xy + y2 – 4)
= 2y[(x + y)2 – 22]
= 2y(x + y + 2)(x + y – 2).