Пошаговое объяснение:

№1

а) 2 1/9 = (2*9 + 1)/9 = (18+1)/9 = 18/9

б) 6 1/7 = (6*7 + 1)/7 = (42+1)/7 = 43/7

в) 3 1/5 = (3*5 + 1)/5 = (15+1)/5 = 16/5

№2

а) 9/7 = 9 : 7 = 1 (ост 2)

9/7 = 1 2/7

б) 40/7 = 40 : 7 = 5 (ост 5)

40/7 = 5 5/7

в) 53/8 = 53 : 8 = 6 (ост 5)

53/8 = 6 5/8

№3

а) 2 2/7 + 4 3/7 = (2+4) + (2+3)/7 = 6 + 5/7 = 6 5/7

б) 7 5/12 + 9 7/12 = (7+9) + (5+7)/12 = 16 + 12/12 = 16 + 1 = 17

в) 15 6/27 - 8 5/27 = (15-8) + (6-5)/27 = 7 + 1/27 = 7 1/27

г) 23 11/16 - 14 9/16 = (23-14) + (11-9)/16 = 9 + 2/16 = 9 2/16 = 9 2/16