Question

Sắp xếp các phân số sau theo thứ tự tăng dần :

a) \(\dfrac{7}{48}\) ; \(\dfrac{11}{72}\) ; \(\dfrac{17}{120}\)

b) \(\dfrac{31}{49}\) ; \(\dfrac{62}{97}\) ; \(\dfrac{93}{140}\)

Answer 1

Giải:

a)

\(\dfrac{7}{48}=\dfrac{105}{720};\)

\(\dfrac{11}{72}=\dfrac{110}{720};\)

\(\dfrac{17}{120}=\dfrac{102}{720}\)

Vì \(102< 105< 110\)

\(\Leftrightarrow\dfrac{102}{720}< \dfrac{105}{720}< \dfrac{110}{720}\)

\(\Leftrightarrow\dfrac{17}{120}< \dfrac{7}{48}< \dfrac{11}{72}\)

Vậy ...

b) \(\dfrac{31}{49}=\dfrac{60140}{95060};\)

\(\dfrac{62}{97}=\dfrac{60760}{95060};\)

\(\dfrac{93}{140}=\dfrac{63147}{95060}\)

Vì \(60140< 60760< 63147\)

\(\Leftrightarrow\dfrac{60140}{95060}< \dfrac{60760}{95060}< \dfrac{63147}{95060}\)

\(\Leftrightarrow\dfrac{31}{49}< \dfrac{62}{97}< \dfrac{93}{140}\)

Vậy ...

Answer 2

a ) \(\dfrac{7}{48}\) = \(\dfrac{105}{720}\)

\(\dfrac{11}{72}\) = \(\dfrac{110}{720}\)

\(\dfrac{17}{120}\) = \(\dfrac{102}{720}\)

Vì 102 < 105 < 110

\(\Leftrightarrow\) \(\dfrac{102}{720}\) < \(\dfrac{105}{720}\) < \(\dfrac{110}{720}\)

\(\Leftrightarrow\) \(\dfrac{17}{120}\) < \(\dfrac{7}{48}\) < \(\dfrac{11}{72}\)

Vậy .....................

( k cho tớ nha . Tớ chỉ bt lm phần a )