Eliminate r: Notice that the coefficients of r are 2 and 3. Their common multiple is 6. We can cause the r-terms to cancel if we multiply the first equation through by (-3), and the second one through by (+2) Then you see that the coefficients of r are equal in magnitude but opposite in sign, so the will cance when we add those equations term by term. --------------- Now we add straight down and the r terms cancel out and we add the other terms --------------- Now in a lot of cases we switch over to substitution, but since is not an integers, it is better to start all over and eliminate the other letter instead. -- Eliminate s: Notice that the coefficients of s are 3 and 2. Their common multiple is 6. We can cause the s-terms to cancel if we multiply the first equation through by (-2), and the second one through by (+3) Then you see that the coefficients of r are equal in magnitude but opposite in sign, so the will cance when we add those equations term by term. --------------- Now we add straight down and the s terms cancel out and we add the other terms --------------- Edwin