\(\dfrac{13}{2}=\dfrac{13x5}{2x5}=\dfrac{65}{10}\)

\(\dfrac{11}{40}=\dfrac{11x25}{40x25}=\dfrac{275}{1000}\)

\(\dfrac{32}{5}=\dfrac{32x2}{5x2}=\dfrac{64}{10}\)

\(\dfrac{21}{250}=\dfrac{21x4}{250x4}=\dfrac{84}{1000}\)

\(\dfrac{1}{200}=\dfrac{1x5}{200x5}=\dfrac{5}{1000}\)

a) \(\frac{{37}}{{100}} = 0,37\);  \(\frac{{ - 34517}}{{1000}} =  - 34,517\)

\(\frac{{ - 254}}{{10}} =  - 25,4\);   \(\frac{{ - 999}}{{10}} =  - 99,9\)

b) \(2 = \frac{2}{1}\);     \(2,5 = \frac{{25}}{{10}}\)

\( - 0,007 = \frac{{ - 7}}{{1000}}\);    \( - 3,053 = \frac{{ - 3053}}{{1000}}\)

\( - 7,001 = \frac{{ - 7001}}{{1000}}\);   \(7,01 = \frac{{701}}{{100}}\).

Bài 1:

5,9 ; 82,45  ;   810,225

Bài 2:

1/10   ;   2/100  ;    4/1000    ;    95/1000

dễ mà bạn

bài 1

5,9;82,45;810,225

bai 2

0,1=1/10   0,02=2/100     0,004=4/1000       0,095=95/1000

ps đc viết dưới dạng số thập phân hữu hạn : \(\frac{1}{4};\frac{13}{50};-\frac{17}{125};\frac{7}{14}\)

ps đc viết dưới dạng só thập phân vô hạn tuần hoàn : \(-\frac{5}{6};\frac{11}{45}\)

\(\frac{1}{4}=0,25;\frac{13}{50}=0,26;-\frac{17}{125}=-0,136;\frac{7}{14}=0,5\)

\(-\frac{5}{6}=-0,8\left(3\right);\frac{11}{45}=0,2\left(4\right)\)

5,5 ; 3,75 ; 6,2

11/2 = 11 x 5 / 2 x 5 = 55/10 , 15/4 = 15 x 25 / 4 x 25 = 375/100 , 31/5 = 31 x 2 / 5 x 2 = 62/10 

11/2 = 5,5

15/4 = 3,75

31/5 = 6,2

\(\frac{13}{2}\)\(=\frac{65}{10}\)\(=6,5\)

\(\frac{11}{40}\)\(=\frac{11x25}{40x25}\)\(=\frac{275}{1000}\)\(=0,275\)

\(\frac{32}{5}\)\(=\frac{64}{10}\)\(=6,4\)

\(\frac{21}{250}\)\(=\frac{84}{1000}\)\(=0,084\)

\(\frac{1}{200}\)\(=\frac{5}{1000}\)\(=0,005\)

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

\(\frac{1}{3}=0,3\)

\(\frac{6}{11}=0,54\)

~ Hok tốt nhé BRO ~ 

1/4=0,25

1/3 =0,(3)

6/11=0,5(45)

\(\dfrac{13}{2}=6,5=\dfrac{65}{10}\)

\(\dfrac{11}{40}=0,275=\dfrac{275}{1000}\)

\(\dfrac{32}{5}=6,4=\dfrac{64}{10}\)

\(\dfrac{21}{250}=0,084=\dfrac{84}{1000}\)

\(\dfrac{1}{200}=0,005=\dfrac{5}{1000}\)

`13/2=7,5`

`11/40=0,275`

`32/5=6,4`

`21/250=0,084`

`1/200=0,005`