Đáp án A

Đáp án A

Đáp án A

\(\frac{1}{4}=\frac{1\times21}{4\times21}=\frac{21}{84}\)

\(\frac{2}{7}=\frac{2\times12}{7\times12}=\frac{24}{84}\)

\(\frac{1}{3}=\frac{1\times28}{3\times28}=\frac{28}{84}\)

\(\Rightarrow\frac{21}{84}< \frac{24}{84}< \frac{28}{84}(21< 24< 28)\)

\(\Rightarrow\frac{1}{4}< \frac{2}{7}< \frac{1}{3}\)

\(\frac{1}{4}=\frac{1x21}{4x21}=\frac{21}{84}\)

\(\frac{2}{7}=\frac{2x12}{7x12}=\frac{24}{84}\)

\(\frac{1}{3}=\frac{1x28}{3x28}=\frac{28}{84}\)

=> \(\frac{21}{84}< \frac{24}{84}< \frac{28}{84}\left(vì21< 24< 28\right)\)

=> \(\frac{1}{4}< \frac{2}{7}< \frac{1}{3}\)

Bé đến lớn :: 7/9  ,   5/6   ,    5/4      ,     21/5

Lớn đến bé : 3/2   ,   5/4   ,   7/10     ,     3/5

3/4   1/2   3/7

3/4 1/2 

giải giúp mình mình cần gấp!!!

=> 5/6; 4/5; 2/3; 7/12; 1/2

                                1/2    ; 4/5    ; 2/3   ; 5/6     ; 7/12

Khi quy đồng ta có: 30/60; 48/60; 40/60; 50/60; 35/60

1/4;2/7;1/3

1/3; 2/7; 1/4

\(\dfrac{1}{4};\dfrac{1}{3};\dfrac{2}{7}=\dfrac{21}{84};\dfrac{28}{84};\dfrac{24}{84}\) 

\(\dfrac{28}{84};\dfrac{24}{84};\dfrac{21}{84}hay\dfrac{1}{3};\dfrac{2}{7};\dfrac{1}{4}\)

\(\dfrac{1}{3};\dfrac{1}{5};\dfrac{3}{10}=\dfrac{10}{30};\dfrac{6}{30};\dfrac{9}{30}\)

\(\dfrac{1}{2};\dfrac{11}{14};\dfrac{6}{7}\)

\(\dfrac{13}{15};\dfrac{5}{6};\dfrac{4}{5}\)