а) х - 6 8/9 = 1 1/6

х - 62/9 = 7/6

х = 7/6 + 62/9

х = 21+124/18

х = 145/18

х = 8 1/18

б) 14 7/8 - у = 10 5/6

119/8 - у = 65/6

119/8 - 65/6 = у

357-260/24 = у

у = 97/24

у = 4 1/24