John Korb wrote: .. [snip] b^2 - 10*b c = --------------- 60 The restated equation for "b" in terms of "c" is: There are two solutions for "b", the above being a quadratic in "b". b = 5 + (1/2)(sqrt(240*c + 100)) and b = 5 - (1/2)(sqrt(240*c + 100)) You can choose the appropriate solution(s) in your case. Kumar HP CSY-India