where the "i"-th row of the "n" × 2 matrix "A" is formula_48, "w" is the 2 × 1 vector ("x, y")T, and the "i"-th element of the column vector "b" is "b""i". If "A" has independent columns, its rank is 2. Then if and only if the rank of the augmented matrix ["A" | "b" ] is also 2, there exists a solution of the matrix equation and thus an intersection point of the "n" lines. The intersection point, if it exists, is given by