(15 1/3-8 3/7)*2 4/7:6 1/21-2 5/8

Расставим действия:

            1          2          3          4  

(15 1/3 - 8 3/7) * 2 4/7 : 6 1/21 - 2 5/8 = 2211/7112.

1) 15 1/3 - 8 3/7 = 46/3 - 59/7 = 322/21 - 177/21 = 145/21;

2) 145/21 * 2 4/7 = 145/21 * 18/7 = 2610/147 = 870/49;

3) 870/49 : 6 1/21 = 870/49 : 127/21 = 870/49 * 21/127 = 870/7 * 3/127 = 2610/889;

4) 2610/889 - 2 5/8 = 2610/889 - 21/8 = 20880/7112 - 18669/7112 = 2211/7112;