Maths problem --- coordinate geometry

(a). A line L: 2x-3y=1 is given. Show that the coordinates (x,y) of any point on the line L can be written as x=2+3k, y=1+2k.

(b). A point P on the line L is equidistant from the lines 2x+y+3=0 and x+2y+5=0. Find the coordinates of P using the result in (a).