Use the Binomial Theorem.

Rewrite using the commutative property of multiplication.

Multiply by .

Apply the product rule to .

Rewrite using the commutative property of multiplication.

Raise to the power of .

Multiply by .

Apply the product rule to .

Rewrite using the commutative property of multiplication.

Raise to the power of .

Multiply by .

Apply the product rule to .

Raise to the power of .

Multiply by .

Expand (x-y)^4