The line l has equation 2x − y − 1 = 0. The line m passes through the point A(0, 4) and is perpendicular to the line l.

a. Find an equation of m.

b. Show that the lines l and m intersect at the point P(2, 3). The line n passes through the point B(3, 0) and is parallel to the line m.

c. Find the coordinates of the point of intersection of the lines l and n.