Пошаговое объяснение:

1)

(х + 5/12) - 9/20 = 11/15

х + 5/12 = 11/15 + 9/20

х + 25/60 = 44/60 + 27/60

х + 25/60 = 31/60

х = 31/60 - 25/60

х = 6/60

х = 1/10

2)

(х - 11/30) - 16/45 = 2/9

х - 11/30 = 2/9 + 16/45

х - 33/90 = 20/90 + 32/90

х - 33/90 = 52/90

х = 52/90 + 33/90

х = 85/90

х = 17/18

3)

(х - 7/15) + 5/8 = 17/24

х - 7/15 = 17/24 - 5/8

х - 56/120 = 85/120 - 75/120

х - 56/120 = 10/120

х = 10/120 + 56/120

х = 66/120

х = 11/20