(5 8/9 : 1 17/36 + 1 1/4) * 5/21 = 1 целая 1/4
1) 5 8/9 : 1 17/36 = 53/9 : 53/36 = 53/9 * 36/53 = 36/9 = 4
2) 4 + 1 1/4 = 5 1/4
3) 5 1/4 * 5/21 = 21/4 * 5/21 = 5/4 = 1 1/4
Пояснения:
5 целых 8/9 = (5*9+8)/9 = 53/9
1 целая 17/36 = (1*36+17)/36 = 53/36
5 целых 1/4 = (5*4+1)/4 = 21/4