1. The problem statement, all variables and given/known data Suppose a, b, and c are integers and x, y, and z are nonzero real numbers that satisfy the following equations: xy/(x+y)=a xz/(x+z)=b yz/(y+z)=c Is x rational? If so, express it as a ratio of two integers. 2. Relevant equations I substituted a lot of equations and I know I need x to equal something. What I got was: x= abcx/(acx+bcx-abx-abc) However I don't know how to solve for x (my algebra skills suck... don't ask me how I made it to discrete mathematics...) 3. The attempt at a solution I know that if I solve for x, I can basically work out the problem on my own.