Q. If the plane 2ax - 3ay + 4az + 6 = 0 passes through the midpoint of the line joining the centres of the spheres $x^2 + y^2 + z^2 + 6x - 8y - 2z = 13$ and $x^2 + y^2 + z^2 -10x + 4y - 2z = 8$ then a equals
Three Dimensional Geometry
Solution: