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
2,(7)=27-2/9=25/9=2 7/9
3,4(9)=349-34/90=315/90=3 45/90
Пошаговое объяснение:
