Ответ:

11. 29/30

Пошаговое объяснение:

1) 11/18 - 7/10 = 55/90 - 63/90 = -8/90 = -4/45

2) 2/9 : (-4/45) = 2/9 * (-45/4) = 1/1 * (-5/2) = -5/2 = -2. 1/2

3) 7 * 2. 1/15 = 7 * 31/15 = 217/15 = 14. 7/15

4) -2. 1/2 + 14. 7/15 =

-2. 15/30 + 14. 14/30 =

-2. 15/30 + 13. 44/30 =

11. 29/30