40) Find the equations of the obtuse angle bisector of the lines 12x - 5y + 7 = 0 and 3y - 4x - 1 = 0.            

42) Find the equations of bisectors of the internal angles of the triangles, the equations of whose sides are x + 1 = 0, 3x - 4y - 5 = 0 and 5x + 12y - 27 = 0. Also, find the co-ordinates of incentre.