6. Find the scalar equation of the plane through the points M(1,2,3) and N(3,2,-1) that is perpendicular to the plane with equation 3x + 2y + 6z +1 = 0.7. Determine the value of k so that the line with parametric equations x = 2 + 3t, y = -2 + 5t, z = k where k=a+tb is parallel to the plane with equation 4x + 3y - 3z -12 = 0