6 5/8 -4 +3 1/8= 9 3/11-(5 2/11+3)= 8 14/15-(3+2/15)=

6 5/8 - 4 + 3 1/8 = (8 * 6 + 5 / 8) - (4 * 8 / 1 * 8) + (8 * 3 + 1 / 8) = 53/8 - 32/8 + 25/8 = 46/8 =

= 6;

9 3/11 - (5 2/11 + 3) = 102/11 - (57/11 + 33/11) = 102/11 - 90/11 = 12/11 = 1 1/11;

8 14/15 - (3 + 2/15) = 134/15 - (45/15 + 2/15) = 134/15 - 47/15 = 87/15 = 5 12/15.