7. Find an equation for the tangent plane and find the parametric equations for the normal line to the given surface at the indicated point. Surface: x+ y-z=7 Point: (1,2,-2) 8. Find any relative maximum, relative minimum, and saddle points and identify what each point is. (By points I mean points on the surface 3 coordinates). Demonstrate using the Second Partial Derivatives Test. f(x, y) = 4xy-x-y