a

x=2.(7)

10x=27.(7)

10x-x = 27.(7) - 2.(7)

9x = 25

x = 25/9

б

x=3.4(9)

10x = 34.(9)

100x=349.(9)

100x - 10x = 349.(9) - 34.(9)

90x = 315

x = 315/90

Verified answer

Ответ:

2,(7)=27-2/9=25/9=2 7/9

3,4(9)=349-34/90=315/90=3 45/90

Пошаговое объяснение: