> va

Sry > và > nha

a, \(\dfrac{23}{27}\) > \(\dfrac{22}{27}\) > \(\dfrac{22}{29}\)

Vậy \(\dfrac{23}{27}\) > \(\dfrac{22}{29}\)

b, \(\dfrac{25}{74}\) > \(\dfrac{24}{74}\) = \(\dfrac{12}{37}\)

Vậy \(\dfrac{25}{74}\) > \(\dfrac{12}{37}\)

hai phân số nào em nhở?

và phân số nào nữa?

b)21/27<21/25<23/25

\(\dfrac{12}{19}< \dfrac{23}{25}\)

\(\dfrac{21}{27}< \dfrac{23}{25}\)

\(\dfrac{12}{19}< \dfrac{23}{25};\dfrac{21}{27}< \dfrac{23}{25}\)

a) \(\dfrac{12}{19}=\dfrac{19}{19}-\dfrac{7}{19}=1-\dfrac{7}{19}\)

\(\dfrac{23}{25}=\dfrac{25}{25}-\dfrac{2}{25}=1-\dfrac{2}{25}\).

-So sánh: \(\dfrac{7}{19}\) và \(\dfrac{2}{25}\).

\(\dfrac{7}{19}=\dfrac{14}{38};\dfrac{2}{25}=\dfrac{14}{175}\Rightarrow\dfrac{7}{19}>\dfrac{2}{25}\left(\dfrac{14}{38}>\dfrac{14}{175}\right)\)

\(\Rightarrow1-\dfrac{7}{19}< 1-\dfrac{2}{25}\) 

\(\Rightarrow\dfrac{12}{19}< \dfrac{23}{25}\)

-Câu b làm tương tự bạn nhé.

a) \(\dfrac{252525}{666666}=\dfrac{25.10101}{66.10101}=\dfrac{25}{66}\)

⇒\(\dfrac{25}{66}=\dfrac{252525}{666666}\)

b: \(\dfrac{23}{24}=1-\dfrac{1}{24}\)

\(\dfrac{24}{25}=1-\dfrac{1}{25}\)

mà \(-\dfrac{1}{24}>-\dfrac{1}{25}\)

nên \(\dfrac{23}{24}>\dfrac{24}{25}\)

a: \(\dfrac{25}{66}=\dfrac{252525}{666666}\)

b: \(\dfrac{23}{24}=1-\dfrac{1}{24}\)

\(\dfrac{24}{25}=1-\dfrac{1}{25}\)

mà \(-\dfrac{1}{24}< -\dfrac{1}{25}\)

nên \(\dfrac{23}{24}< \dfrac{24}{25}\)

a) Có : 23/27>22/27

Mà 22/27>22/29

=> 23/27>22/29

b) Có : 12/25=24/50

24/50<24/49;24/49<25/49

=> 12/25<25/49

a,23/27>23/29

22/29<23/29

=>22/29<23/29<23/27

=>22/29<23/27

kl:....(kết luận)

a) Ta có \(\dfrac{23}{27}>\dfrac{23}{29};\dfrac{23}{29}>\dfrac{22}{29}\)

Vậy \(\dfrac{23}{27}>\dfrac{22}{29}\)

b) Ta có \(\dfrac{15}{25}=1-\dfrac{2}{5}\)

\(\dfrac{25}{49}=1-\dfrac{24}{49}\)

Vì \(\dfrac{2}{5}=\dfrac{24}{60}< \dfrac{24}{49}\)

Vậy \(\dfrac{15}{25}>\dfrac{25}{49}\)

23/27 lớn hơn 22/29

15/25 lớn hơn 25/49

-24/25 và -23/27

Ta có : -24/25 - 1/25 = -1

           -23/27 - 4/27 =-1

Ta lại có : -1/25 = -4/100 < -4/27

Vậy -24/25 > -23/27

-23/12 và -5/2

Ta có: -5/2=-30/12

Vì -23>-30 Nên -23/12 > -30/12

Vậy -23/12 > -5/2

a)Vì:\(-\frac{24}{25}< -\frac{23}{25}\)

      Mà \(-\frac{23}{25}< -\frac{23}{27}\)

Suy ra:\(-\frac{24}{25}< -\frac{23}{27}\)

b)Vì \(-\frac{24}{12}< -\frac{23}{12}\)

            Hoặc \(-2< -\frac{23}{12}\)

       Mà \(-\frac{5}{2}< -2\)

Suy ra:\(-\frac{5}{2}< -\frac{23}{12}\)