TA CÓ 12*2=24<25, 2582=50>49

=>12/25<25/49

Ta có:

\(\frac{12}{25}< \frac{12}{24}=\frac{1}{2}\Rightarrow\frac{12}{25}< \frac{1}{2}\left(1\right)\)

\(\frac{25}{49}>\frac{25}{50}=\frac{1}{2}\Rightarrow\frac{25}{49}>\frac{1}{2}\left(2\right)\)

Từ \(\left(1\right)\)và\(\left(2\right)\)\(\Rightarrow\)\(\frac{12}{25}< \frac{1}{2}< \frac{25}{49}\)\(\Rightarrow\frac{12}{25}< \frac{25}{49}\)

NHỚ TK MK NHA

\(\frac{12}{25}\)= 12: 25 0,48 

\(\frac{25}{49}\)= 0,510..........

=> 0,48 < 0,510 => \(\frac{12}{25}\)<    \(\frac{25}{49}\)

Ta có :

\(\frac{15}{25}=\frac{15\times49}{25\times49}=\frac{735}{1225};\frac{25}{49}=\frac{25\times25}{49\times25}=\frac{625}{1225}\)

Vì 735 > 625 nên \(\frac{15}{25}>\frac{25}{49}\)

Ta có:

\(\frac{25}{12}>\frac{24}{12}=2\)

\(\frac{49}{25}< \frac{50}{25}=2\)

Vì  \(\frac{25}{12}>2>\frac{49}{25}\) nên  \(\frac{25}{12}>\frac{49}{25}\)

Chúc bạn học tốt!

12/25 < 25/49

13/15 > 133/155

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

câu 1 : quy đồng 2 ps ta đc : \(\frac{621}{756},\frac{672}{756}\) mà \(\frac{621}{756}

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)