Ответ:

х = 1/9

Пошаговое объяснение:

5 5/12х - 2 3/14 = 5 1/4х - 3 5/7

5 5/12х - 5 1/4х = 3 5/7 - 2 3/14

65/12х - 21/4х = 26/7 - 31/14

65/12х - 21/4х * 3 = 26/7 * 2 - 31/14

65/12х - 63/12х = 52/14 - 31/14

2/12х = 21/14

х = 21/14 : 2/12

х= 1/9