Recent content by clone

Thanks! I see now that I was looking at what actually needed to be proved from completely the wrong way

I don't really understand what any of that means to be honest. I guess I should have been more specific about the context. This is from Serge Lang's basic mathematics, and in the section titled "Intuitive Geometry". We are just doing 2d geometry, drawing diagrams on paper. The definition of...

The proof in the solutions was done much differently then mine (much simpler), so I would like feedback on whether my proof is valid or not. Assume that F(L) and F(K) are not parallel, then they necessarily intersect. Let X' be the point of intersection. Then X' lies on both F(L) and F(K). Let...

Relevant Rules: N5: -(a+b) = - a - b N4: a = -(-a) N2: a + (-a) = 0 and -a + a = 0 I tried just manipulating -(a - b) with the rules to get the answer: -(a - b) = -(a + (-b)) With N5: = - a + (-(-b)) With N4: = - a + b Commutativity: b - a The provided solution in the book used N2 to prove it...