A loan is repaid by level payments at the end of each month. The principal outstanding on May 1, 1996, was Q\ on May 1, 1997, was R; on May 1, 1998, was S; on May 1, 1999, was T. Determine whether or not each of the following is true:

(a) Q+T

(b) {Q + RXS-\-T) = {R + Sf

(c) {Q-R){S-T) = {R-Sf AppendixLO1