Rewrite as .

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

Multiply by .

Move to the left of .

Rewrite as .

Multiply by .

Move to the left of .

Rewrite as .

Rewrite as .

Rewrite as .

Multiply by .

Reorder and .

Add and .

Subtract from .

Subtract from .

Move .

Multiply ((p+r)-1)^2