7. Find the distance from the point (1,2,3) to the line r3t, y=1-5t, z=−3+7t. 8. Find the distance from the point (0,1,-1) to the plane x+y-z=1. 9. Find parametric equations for the line of intersection of the planes x-3y+5: 7 and 2x+y-3: 1. 10. Find the distance between the non-intersecting lines z-1-1,y=2+31, 2-3-21 and z 5+s, y--3-2s, -2+3s.