\(0,\left(1\right)=\dfrac{1}{9}\)

\(0,\left(01\right)=\dfrac{1}{99}\)

\(1,\left(8\right)=\dfrac{187}{99}=\dfrac{187:11}{99:11}=\dfrac{17}{9}\)

\(0,\left(27\right)=\dfrac{27}{99}=\dfrac{27:9}{99:9}=\dfrac{3}{11}\)

1. a) -0,35 = -7/20 ; b) 1,14 = 57/50

  c) 2,108 = 527/250 ; -0,725 = -29/40

2. a) 0,2(3) = 0,2 + 0,0(3) = 0,2 + 0,3. 0,(1) = 0,2 + 0,3.1/9 = 1/5 + 1/30 = 7/30 

  b 1,4(51) = 1,4 + 0,0(51) = 7/5 + 5,1. 0,(01) = 7/5 + 5,1. 1/99 = 7/5 + 17/330 = 479/330

  c) -2,(412) = -2 - 0,(412) = -2 - 412. 0,(001) = -2 - 412. 1/999 = -2 - 412/999 = -2410/999

d) 3,1(45) = 3,1 + 0,0(45) = 3,1 + 4,5. 0,(01) = 3,1 + 4,5 . 1/99 = 3,1 + 1/22 = 173/55

3. Ta có: -2,(6).x = 0,1(6)

=> [-2 - 0,(1).6].x = (0,1 + 0,6. 0,(1)]

=> (-2 - 2/3)x = 0,1 + 1/15

=> -8/3x = 1/6

=>  x = 1/6 : (-8/3)

=> x = -1/16

c: \(-0.4\left(6\right)=-\dfrac{7}{15}\)

d: \(1,\left(09\right)=\dfrac{12}{11}\)

a) \(\dfrac{125}{100}\)

b) 0,25

c) 1/2

a: 125%=5/4

b: 1/4=0,25

c: 50%=1/2

a: 125%=5/4

b: 1/4=0,25

c: 50%=1/2

0,(6)=2/3

0,(24)=8/33

2,(1485)=217/101

0,6=2/3

0,24= 6/25

2,1485=217/101

0,(4)=4/9

1,(2)=11/9

0,0(8)=4/45

0,1(2)=11/90

a: \(-1,\left(3\right)=-\dfrac{4}{3}\)

b: \(0,\left(72\right)=\dfrac{8}{11}\)

168 phần 25

\(\frac{168}{25}\)

k mình nhé !

1,12(6) = \(1+\frac{126-12}{900}=1+\frac{114}{900}=1+\frac{19}{150}=\frac{150}{150}+\frac{19}{150}=\frac{169}{150}\)

\(-0.025=\dfrac{-25}{1000}=\dfrac{-1}{40}\)

\(-0.033=\dfrac{-33}{1000}\)

-0,025= \(\dfrac{-1}{40}\)

-0,033= \(\dfrac{-33}{1000}\)

-0,025 = \(\dfrac{-25}{1000}\)=\(\dfrac{-1}{40}\)

-0,033 = \(\dfrac{-33}{1000}\)