Simplify :(3x + 2y - 9) (2x - 6y + 2) - [(4x - 9y - 1) + (-3x + 8y + 7)]
Equation of a line which is parallel to the line common to the pair of lines given by 6x2−xy−12y2−0 and 15x2+14xy−8y2−0 and at a distance 7 from it is