(5 1/14 + 31/63 - (2 31/252)) * 24 : 12/35 = 240 целых 5/6
1) 5 1/14 + 31/63 = 5 9/126 + 62/126 = 5 71/126
2) 5 71/126 - 2 31/252 = 5 142/252 - 2 31/252 = 3 111/252 = 3 37/84
3) 3 37/84 * 24 = 289/84 * 24 = (289*2)/7 = 578/7
4) 578/7 : 12/35 = 578/7 * 35/12 = (289*5)/(1*6) = 1445/6 = 240 5/6
Пояснения:
1/14 = 9/126 - доп.множ. 9
31/63 = 62/126 - доп.множ. 2
71/126 = 142/252 - доп.множ. 2
111/252 = 37/84 - сократили на 3
3 37/84 = (3*84+37)/84 = 289/84