For (A.) Get a common denominator, 40/12 - 9/12 = 31/12 or (2 and 7/12) For (B.) Get a common denominator, 24/15 - 10/15 = 14/15 (Simplified) For (C.) Get a common denominator, 51/30 - 25/30 = 26/30 or (13/15) For (D.) Get a common denominator, 14/6 - 9/6 = 5/6 (Simplified)