или 25/9
X=0,(21)
100x=21,(21)
100x-x=21,(21)-0,(21)
99x=21 // : 99
X=21/99=7/33
2)
X=2,(7)
10x=27,(7)
10x-x=27,(7)-2,(7)
9x=25 // :9
X=25/9
3)
X=0,(19)
100x=19,(19)
100x-x=19,(19)-0,(19)
99x=19 //: 99
X=19/99
или 25/9
X=0,(21)
100x=21,(21)
100x-x=21,(21)-0,(21)
99x=21 // : 99
X=21/99=7/33
2)
X=2,(7)
10x=27,(7)
10x-x=27,(7)-2,(7)
9x=25 // :9
X=25/9
3)
X=0,(19)
100x=19,(19)
100x-x=19,(19)-0,(19)
99x=19 //: 99
X=19/99