2/3*8/13 = 12/49*7/24 2 4/5 * 10 1 5/16 * (9-2 1/7) (8,8:1,6-3,05) * 1,4

Делаем умножения.

1) 2/3 * 8/13 = (2 * 8) / (3 * 13) = 16/39;

2) 12/49 * 7/24 = (12 : 12) / (49 : 7) * (7 : 7) / (24 : 12) = 1/7 * 1/2 = 1/14;

3) 2 4/5 * 10 = (2 * 5 + 4) / 5 * 10 = (10 + 4) / 5 * 10 = 14/5 * 10 = 14 / (5 : 5) * (10 : 5) = 14 * 2 = 28;

4) 1 5/16 * (9 - 2 1/7) = (1 * 16 + 5) / 16 * (9 - (2 * 7 + 1) / 7)) = 21/16 * (9 - 15/7) = 21/16 * (9 * 7/7 - 15/7) = 21/16 * (63/7 - 15/7) = 21/16 * 48/7 = (21 : 7) / (16 : 16) * (48 : 16) / (7 : 7) = 3/1 * 3/1 = 3 * 3 = 9;

5) (8,8 : 1,6 - 3,05) * 1,4 = (5,5 - 3,05) * 1,4 = 2,45 * 1,4 = 3,43 = 3,4.