The centroid of the triangle with vertices A(2, $$-$$3, 3), B(5, $$-$$3, $$-$$4) and C(2, $$-$$3, $$-$$2) is the point

What is the radius of the sphere $${x^2} + {y^2} + {z^2} - 6x + 8y - 10z + 1 = 0$$ ?

The equation of the plane passing through the intersection of the planes 2x + y + 2z = 9, 4x $$-$$ 5y $$-$$ 4z = 1 and the point (3, 2, 1) is

The distance between the parallel planes $$4x - 2y + 4z + 9 = 0$$ and $$8x - 4y + 8z + 21 = 0$$