(81/4-3/8):31/2:((5-42/5)*10)+(31/8-17/8)*13/4:((2-13/8):31/8)

Наверно правильно будет так:(8 1/4 - 3/8) : 3 1/2 : ((5 - 4 2/5) * 10) + ( 3 1/8 - 1 7/8) * 1 3/4 : ((2 - 1 3/8) : 3 1/8);1) 8 1/4 - 3/8 = 8 2/8 - 3/8 = 7 10/8 - 3/8 = 7 7/8;2) 7 7/8 : 3 1/2 = 63/8 : 7/2 = 63/8 * 2/7 = 9/4 * 1/1 = 9/4 = 2 1/4;3) 5 - 4 2/5 = 4 5/5 - 4 2/5 = 3/5;4) 3/5 * 10 = 3/5 * 10/1 = 3/1 * 2/1 = 6/1 = 6;5) 2 1/4 : 6 = 9/4 : 6/1 = 9/4 * 1/6 = 3/4 * 1/2 = 3/8;6) 3 1/8 - 1 7/8 = 2 9/8 - 1 7/8 = 1 2/8 = 1 1/4;7) 1 1/4 * 1 3/4 = 5/4 * 7/4 = 35/16 = 2 3/16;8) 2 - 1 3/8 = 1 8/8 - 1 3/8 = 5/8;9) 5/8 : 3 1/8 = 5/8 : 25/8 = 5/8 * 8/25 = 1/1 * 1/5 = 1/5;10) 2 3/16 : 1/5 = 35/16 * 5/1 = 175/16 = 10 15/16;11) 3/8 + 10 15/16 = 6/16 + 10 15/16 = 10 21/16 = 11 5/16.Ответ: 11 5/16.