1) 15 4/9-4 4/9* 3 3/8 = 15 4/9 - 40/9 * 27/8 = 15 4/9 - 5*3 = 15 4/9 - 15 = 4/9
2) 81/88 * (6 - 1 13/15 * 1 19/21) = 81/88 * (6 - 28/15 * 40/21) = 81/88 * (6 - 4/3 * 8/3) = 81/88 * (6 - 32/9) = 81/88 * (5 9/9 - 3 5/9) = 81/88 * 2 4/9 = 81/88 * 22/9 = 9/4 = 2 1/4
3) (5 1/16 - 1 1/8)*(5/6 + 3/14) = (4 17/16 - 1 2/16)*(35/42 + 9/42) = 3 15/16 * 44/42 = 63/16 * 44/42 = 3/4 * 11/2 = 33/8 = 4 1/8
4)5 1/16 - 1 1/8 * (5/6 + 3/14) = 5 1/16 - 9/8 * (35/42 + 9/42) = 5 1/16 - 9/8 * 44/42 = 5 1/16 - 3/2 * 11/14 = 5 1/16 - 33/28 = 5 7/112 - 132/112 = 3 231/112 - 132/112 = 3 99/112