Rewrite as .
Expand using the FOIL Method.
Apply the distributive property.
Apply the distributive property.
Apply the distributive property.
Simplify and combine like terms.
Simplify each term.
Multiply by .
Rewrite using the commutative property of multiplication.
Multiply by .
Multiply by .
Multiply by .
Subtract from .
Move .
Subtract from .
Subtract from .
Add and .
Simplify (h-k)^2-k^2