hi, I have a very simple expression: -(y*(G2-G1)+x*(-G2-G1)-n)/2 and I want to transform it in a form like: (G1-G2)y (G2+G1)x n ------------- + --------- + ---- 2 2 2 It looks simple, I've tried with ratsimp(%,x,y) but I cant figure out how to manage the sign and the denominator, could someone please help? thanks andrea