\(\dfrac{14}{21};\dfrac{60}{72}\)

\(\dfrac{60}{72}=\dfrac{5}{6}=\dfrac{5\cdot21}{6\cdot21}=\dfrac{105}{126}\)

\(\dfrac{14}{21}=\dfrac{14\cdot6}{21\cdot6}=\dfrac{84}{126}\)

\(\dfrac{84}{123}< \dfrac{105}{126}\Rightarrow\dfrac{14}{21}< \dfrac{60}{72}\)

\(\dfrac{38}{133};\dfrac{129}{344}\)

\(\dfrac{38}{133}=\dfrac{19}{7}=\dfrac{19\cdot8}{7\cdot8}=\dfrac{152}{56}\)

\(\dfrac{129}{344}=\dfrac{3}{8}=\dfrac{3\cdot7}{8\cdot7}=\dfrac{21}{56}\)

\(\dfrac{152}{56}>\dfrac{21}{56}\Rightarrow\dfrac{38}{133}>\dfrac{129}{344}\)

ta có: -14/21=-2/3

         -60/-72=5/6

ta lại có:-2/3=-4/6

=>-14/21<-60/-72

Ta có :\(\frac{-14}{21}=\frac{-2}{3}< 0\)

Ta thấy \(\frac{-60}{-72}=\frac{60}{72}=\frac{5}{6}>0\)

Vì \(\frac{-2}{3}< 0;\frac{5}{6}>0\)

Nên \(\frac{5}{6}>\frac{-2}{3}\)

Hay \(\frac{-14}{21}< \frac{-60}{-72}\)

Vậy ......

ta có : \(\frac{-14}{21}=\frac{-2}{3};\frac{-60}{-72}=\frac{-5}{-6}=\frac{5}{6}\)

Quy đồng : \(\frac{-2}{3}=\frac{\left(-2\right).2}{3.2}=\frac{-4}{6};\frac{5}{6}\)giữ nguyên

Vì \(\frac{-4}{6}< \frac{5}{6}\) \(\Rightarrow\frac{-14}{21}< \frac{-60}{-72}\)

Cách 1 :

\(\frac{-60}{-72}\)\(=\frac{60}{72}=\frac{5}{6}\)

\(\frac{-14}{21}=\frac{-2}{3}\)

Vì \(\hept{\begin{cases}6⋮3\\6⋮6\end{cases}}\Rightarrow BCNN\left(6;3\right)=6\Rightarrow MC=6\)

Có: \(\frac{-2}{3}=\frac{\left(-2\right).2}{3.2}=\frac{-4}{6}\)giữ nguyên \(\frac{5}{6}\).

Vì - 4 < 5 nên \(\frac{-4}{6}< \frac{5}{6}\)hay \(\frac{-14}{21}< \frac{-60}{-72}\)

C2 : Thấy : \(\frac{-14}{21}< 0;\frac{-60}{-72}=\frac{60}{72}>0\)

\(\Rightarrow\frac{-14}{21}< \frac{-60}{-72}\)

Cách 1\(\frac{-14}{21}=\frac{-14:7}{21:7}\frac{2}{3}\)

\(\frac{-60}{-72}=\frac{-60:(-12)}{-72:(-12)}=\frac{5}{6}\)

Cách 2 : Tự làm

So sánh mk nhầm :D

Cách 1 : \(\frac{-14}{21}=\frac{-14:7}{21:7}=\frac{-2}{3}\)

\(\frac{-60}{-72}=\frac{-60:(-12)}{-72:(-12)}=\frac{5}{6}\)

Mà \(\frac{-2}{3}< \frac{5}{6}\Rightarrow\frac{-14}{21}< \frac{-60}{-72}\)

Cách 2 : Ta thấy : \(\frac{-14}{21}< 0,\frac{-60}{-72}>0\)

=> \(\frac{-14}{21}< \frac{-60}{-72}\)

Chịu nhé

\(\dfrac{60}{72}>\dfrac{14}{21}\)              \(\dfrac{19}{31}>\dfrac{17}{35}\)                   \(\dfrac{18}{53}>\dfrac{26}{78}\)    

a -35/50 = -7/10

b  510/2805 = 2/11

c  119/126

B2

-2/3= -8/12 , -1/4= -3/12

-8/12<-3/12 nên -2/3<-1/4

b 2/3  5/6

12/18 và 15/18

12/18<15/18

nên 14/21<60/72

bài 1 :

a) = -7/10

b) = 510/2805 = 2/11

c) = 17/18

Bài 52 :

a) 14/21 = 2/3 và 60/72 = 5/6

Vì 2/3 = 4/6 < 5/6 nên 2/3 < 5/6

Bài 53 :

a) Vì 200 < 314 nên 17/200 > 17/314

b) Ta có 11/54 < 11/37 < 22/37 nên 11/54 < 22/37

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a . 21/70 = 3/10 ; 56/96 = 7/12 ; 60/72 = 15/18

Mình chỉ làm tới đây thôi .

a) `14/21=(14:7)/(21:7)=2/3=4/6`

`60/72=(60:12)/(72:12)=5/6`

Vì `4/6 <5/6`

`=> 14/21 < 60/72`

b) `22/37 = (22:2)/(37:2)= 11/(37/2)`

Vì `54 > 37/2`

`=> 11/54 < 22/37`