19-2 2/15*3*1/8*9/14

Выполним сначала умножение по очереди, а после этого отнимание:

19 - 2 2/15 * 3 * 1/8 * 9/14 = 18 17/35.

1) 2 2/15 * 3 = (2 * 15 + 2) / 15 * 3 = (30 + 2) / 15 * 3 = 32/15 * 3 = (32 * 3) / 15 = (32 * 3) / (5 * 3) = 32/5 = 6 (32 - 6 * 5) / 5 = 6 (32 - 30) / 5 = 6 2/5;

2) 6 2/5 * 1/8 = 32/5 * 1/8 = (32 * 1) / (5 * 8) = (4 * 8) / (5 * 8) = 4/5;

3) 4/5 * 9/14 = (4 * 9) / (5 * 14) = (2 * 2 * 9) / (5 * 2 * 7) = (2 * 9) / (5 * 7) = 18/35;

4) 19 - 18/35 = 18 + 1 - 18/35 = 18 + 35/35 - 18/35 = 18 + (35 - 18) / 35 = 18 + 17/35 = 18 17/35.