Factoring Check my work please, and explain why (0_0)?

Question

Given: (x-y)²-3(y-x)³=

my work: (x-y)²3(x-y)³= Note: ³ gives you a (-)'s.
1) (x-y)(3x-3y)
2) 3(x-y)(x-y)

This is completly wrong I don't get this, I need help in explain why's. Please help me, PLEASE

Answer 1

(x-y)^3 - 3(y-x)^3

= (x-y)^3 + 3[(-1)^3(y-x)^3]

= (x-y)^3 + 3(x-y)^3

= 4(x-y)^3.