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

Combine the opposite terms in .

Reorder the factors in the terms and .

Subtract from .

Add and .

Reorder the factors in the terms and .

Subtract from .

Add and .

Simplify each term.

Multiply by .

Multiply by .

Multiply by by adding the exponents.

Move .

Multiply by .

Reorder and .

Add and .

Simplify (a+b-c)(a+b+c)