If $\;(x+iy)^{3}=u+iv\;$ , then show that $\; \large\frac{u}{x} + \large\frac{v}{y} = 4(x^{2}-y^{2})$

Question

$(a)\;4(x^{2}-y^{2})\qquad(b)\;4(y^{2}-x^{2})\qquad(c)\;4(y-x)\qquad(d)\;4(x-y)$