Решите пример 3 целых 3/7×1целая 1/6- 7/15×1 целая 19/21

3 3/7 * 1 1/6 - 7/15 * 1 19/21 = 3 1/9

1) 3 3/7 * 1 1/6 = 24/7 * 7/6 = 24/6 = 4
2) 7/15 * 1 19/21 = 7/15 * 40/21 = (1*8)/(3*3) = 8/9
3) 4 - 8/9 = 3 целых 9/9 - 8/9 = 3 1/9