The general form ax + by + c = 0 is the universal representation. Slope = -a/b (when b is not 0). x-intercept = -c/a, y-intercept = -c/b. To convert to normal form, divide by sqrt($a^2$ + $b^2$) and adjust sign so that the constant term is positive. The general form is mandatory for applying the distance formula and for comparison of coefficients.