Question

How do you simplify `p(p-q) + q(q-r) + r(r-p)`?

Answer 1

There isn't much to simplify, but you can get rid of the brackets:

`=p^2-pq+q^2-qr+r^2-pr`

And maybe re-arrange:

`p^2+q^2+r^2-pq-pr-qr`

Doesn't look much simpler to me...