[F4 A.Math] Coordinate Geometry : family of straight lines

two side of △ABC are:
AB : 3x + 5y -13 = 0
AC : 11x + 7y +9 =0

H ( 12, 9 ) is the orthocentre of △ABC
the equation of the altitude AD is : x - 4y +24 =0

***Find the equation of BC