Ответ:

15 3/8 : (2 3/4х+5 5/6) - 1 1/2 = 3/4

15 3/8 : (2 3/4х+5 5/6) = 1 1/2 + 3/4

15 3/8 : (2 3/4х+5 5/6) = 1 2/4 + 3/4

15 3/8 : (2 3/4х+5 5/6) = 2 1/4

15 3/8 : (2 3/4х+5 5/6) = 2,25

(2 3/4х+5 5/6) = 15 3/8 : 2 1/4

(2 3/4х+5 5/6) = 123/8 • 4/9

(2 3/4х+5 5/6) = 41/2 • 1/3

(2 3/4х+5 5/6) = 41/6

(2 3/4х+5 5/6) = 6 5/6

2 3/4х = 6 5/6 - 5 5/6

2 3/4х = 1

х = 1 : 2 3/4

х = 1/1 • 4/11

х = 4/11