Rút gọn :

Vì 38/133 =2/7 ;129/344=3/8

quy đồng2/7= 16/56;3/8=21/56

vì 16/56<21/56=>38/133<129/344

Haizz lần đâu tiên tự làm lâu vãi @.@

Ta có :

38/133=13072/45752

129/344=17157/45752

Vì 13072/45752<17157/45752

=>38/133<129/344

Vậy 38/133<129/344

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

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

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

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

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

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

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

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

\(\frac{38}{133}=\frac{2}{7}\)

\(\frac{129}{344}=\frac{3}{8}\)

So sánh: \(\frac{2}{7}và\frac{3}{8}\) nhé!

Rút gọn:\(\frac{38}{133}\)= \(\frac{2}{7}\); \(\frac{129}{344}\)= \(\frac{3}{8}\)

Quy đồng: MC= BCNN(7,8)=56 

\(\frac{2}{7}\)= \(\frac{16}{56}\); \(\frac{3}{8}\)=\(\frac{21}{56}\)

So sánh: Vì\(\frac{16}{56}\)< \(\frac{21}{56}\)==> \(\frac{38}{133}\)< \(\frac{129}{344}\)

Chúc bạn học tốt nhé.

Ta có : 

\(1-\frac{38}{133}=\frac{133}{133}-\frac{38}{133}=\frac{95}{133}=\frac{5}{7}\)

\(1-\frac{129}{344}=\frac{344}{344}-\frac{129}{344}=\frac{215}{344}=\frac{5}{8}\)

Vì \(\frac{5}{7}>\frac{5}{8}\) nên \(\frac{38}{133}< \frac{129}{344}\)

\(\Rightarrow\)\(\frac{38}{-133}>\frac{-129}{344}\)

Vậy \(\frac{38}{-133}>\frac{-129}{344}\)

38/133<129/344

tk nha

Ta có : 

\(1-\frac{38}{133}=\frac{5}{7}\)

\(1-\frac{129}{344}=\frac{5}{8}\)

Vì \(\frac{5}{7}>\frac{5}{8}\) nên \(\frac{38}{133}< \frac{129}{344}\)

Vậy \(\frac{38}{133}< \frac{129}{344}\)

\(\frac{38}{133}=\frac{2}{7}\)

\(\frac{129}{344}=\frac{3}{8}\)

\(\frac{2}{7}=\frac{16}{56}\)  ;   \(\frac{3}{8}=\frac{24}{56}\)

vì \(16< 24\)nên \(\frac{2}{7}< \frac{3}{8}\)

hay \(\frac{38}{133}< \frac{129}{344}\)

P/S Toán lớp 9????

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

sxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

đề bài là j???

Đề: So sánh:

e: 38/133=2/7=16/56

129/344=3/8=21/56

mà 16<21

nên 38/133<129/344

f: 11/54=22/108<22/37

a: 14/21=2/3=4/6

60/72=5/6

mà 4<5

nên 14/21<60/72

b: 38/133=2/7=16/56

129/344=3/8=21/56

mà 16<21

nên 38/133<129/344