a ) 1,75 = 7 4 b ) − 3,12 = − 78 25

c ) 0,63 = 63 100 . d ) − 2,19 = − 219 100

a)  1 , 32   =   33 25

b)  - 3 , 5 =   - 7 2

c)  0 , 84   =   21 25

d)  - 2 , 38   =   119 50

a) 1,32 = 33 25                              

b) -3,5= - 7 2

c) 0,84 = 21 25                                      

d) -2,38 =  119 50

a: \(=-\dfrac{7}{20}\)

b: \(=\dfrac{9}{4}\)

c: \(=-\dfrac{17}{25}\)

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

a, 0.4=\(\frac{4}{10}\) =\(\frac{2}{5}\)

0,02=\(\frac{2}{100}\)=\(\frac{1}{50}\)

b,0,6 = \(\frac{6}{10}\)=\(\frac{3}{5}\)

0,05=\(\frac{5}{100}\)=\(\frac{1}{20}\)

c, 1,2=\(\frac{12}{10}\)=\(\frac{6}{5}\)

0,25= \(\frac{25}{100}\)=\(\frac{1}{4}\)

d, 2,5 = \(\frac{25}{10}\)=\(\frac{5}{2}\)

0,75 = \(\frac{75}{100}\)= \(\frac{3}{4}\)

\(0,75=\dfrac{75}{100}=\dfrac{75:25}{100:25}=\dfrac{3}{4}\\ 0,8=\dfrac{8}{10}=\dfrac{8:2}{10:2}=\dfrac{4}{5}\\ 2,15=\dfrac{215}{100}=\dfrac{215:5}{100:5}=\dfrac{43}{20}\)

A) \(0,75=\dfrac{75}{100}=\dfrac{75:25}{100:25}=\dfrac{3}{4}\)

B) \(0,8=\dfrac{8}{10}=\dfrac{8:2}{10:2}=\dfrac{4}{5}\)

C) \(2,15=\dfrac{215}{100}=\dfrac{215:5}{100:5}=\dfrac{43}{20}\)

a) \(0,75=\dfrac{3}{4}\)

b) \(0,8=\dfrac{4}{5}\)

c) \(2,15=\dfrac{43}{20}\)

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

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