4 * 8 4/9 - 4 3/7 * 6 4/9 = 5 целых 5/21
1) 4 * 8 4/9 = 4 * 76/9 = 304/9 = 33 целых 7/9
2) 4 3/7 * 6 4/9 = 31/7 * 58/9 = 1798/63 = 28 целых 34/63
3) 33 7/9 - 28 34/63 = 33 49/63 - 28 34/63 = 5 15/63 = 5 5/21
Пояснения:
8 целых 4/9 = (8*9+4)/9 = 76/9
4 целых 3/7 = (4*7+3)/7 = 31/7
6 целых 4/9 = (6*9+4)/9 = 58/9
7/9 = 49/63 - доп.множ. 7
15/63 = 5/21 - сократили на 3