where both ''A'' and ''B'' are not both equal to zero. The equation is usually written so that ''A'' ≥ 0, by convention. The [[Cartesian coordinate system|graph]] of the equation is a [[line (geometry)|straight line]], and every straight line can be represented by an equation in the above form. If ''A'' is nonzero, then the ''x''-intercept, that is, the ''x''-[[coordinate]] of the point where the graph crosses the ''x''-axis (where, ''y'' is zero), is ''C''/''A''. If ''B'' is nonzero, then the ''y''-intercept, that is the ''y''-coordinate of the point where the graph crosses the ''y''-axis (where x is zero), is ''C''/''B'', and the [[slope]] of the line is −''A''/''B''. The general form is sometimes written as:
: <math>ax + by + c = 0, \,</math>
where ''a'' and ''b'' are not both equal to zero. The two versions can be converted from one to the other by moving the constant term to the other side of the equal sign.
