Talk:Field axioms zero product proof/@comment-92.232.167.138-20120723094943

Not sure how to edit this page, maybe I'm being stupid but to prove -1(m) = -m all you need to note is that m.0 = m.(0+0) = m.0 + m.0 so subtracting m.0 from both sides gives m.0 = 0 as 0 = 1+(-1), m.0 = m.(1+(-1)) = m + -1(m) = 0 so subtracting m from both sides gives -1(m) = (-m)