Rewrite as .

Expand by multiplying each term in the first expression by each term in the second expression.

Multiply by .

Rewrite using the commutative property of multiplication.

Move to the left of .

Rewrite as .

Multiply by .

Multiply by .

Multiply by .

Multiply .

Multiply by .

Multiply by .

Rewrite as .

Multiply .

Multiply by .

Multiply by .

Multiply by .

Move .

Subtract from .

Subtract from .

Add and .

Move .

Simplify (a-b-1)^2