8. Show that B = XY-nXY LX-nX2 where B is the OLS slope estimator. Hint: Prove that: the numerators are equal, i.e. the denominators are equal, i.e. (X-X)(Y-) ()2 XX;-nXY-(X-X) (Y; -), and - XnX = 1 (X-X) For both of these proofs, the easiest way to proceed is to start with the right hand sides and use algebra to arrive at the left hand sides.