6 3/7 : 1 6/7 = 4,5у
45/7 : 13/7 = 4,5у
45/7 * 7/13 = 4,5у
45/13 = 45/10у
у = 45/13 : 45/10
у = 45/13 * 10/45
у = 10/13
Проверка: 45/13 = 4,5 * 10/13
45/13 = 45/13
Пояснения:
6 3/7 = (6*7+3)/7 = 45/7
1 6/7 = (1*7+6)/7 = 13/7
4,5 = 4 5/10 = (4*10+5)/10 = 45/10