Пошаговое объяснение:

5/6(1/2х - 2/3) = 3х - 2 1/4

5/12х - 10/18 = 3х - 2 1/4

5/12х - 3х = -2 1/4 + 10/18

5/12х - 2 12/12х = -2 9/36 + 20/36

-2 7/12х = -1 45/36 + 20/36

-2 7/12х = -1 25/36

-31/12х = -61/36

х = -61/36 : (-31/12)

х = -61/36 * (-12/31)

х = -61/3 * (-1/31)

х = 61/93