Đổi hết ra số thập phân mà so sánh ý bạn.

a) \(\dfrac{3}{124}=0,02419\)

\(\dfrac{1}{41}=0,02439\)

\(\dfrac{5}{207}=0,02415\)

\(\dfrac{2}{83}=0,02409\)

Có \(\dfrac{2}{83}=0,02409\) < \(\dfrac{5}{207}=0,02415\) < \(\dfrac{3}{124}=0,02419\) < \(\dfrac{1}{41}=0,02439\)

Vậy..............

Cứ tương tự như vậy mà làm nhé .Tớ buồn ngủ lắm :(

\(\dfrac{-49}{78}< \dfrac{64}{-95}\)

\(A=1\cdot3\cdot5\cdot7\cdot\ldots\cdot49\)

\(=\frac{1\cdot2\cdot3\cdot\ldots\cdot50}{2\cdot4\cdot6\cdot\ldots\cdot50}\)

\(=\frac{1\cdot2\cdot3\cdot\ldots\cdot50}{2\cdot1\cdot2\cdot2\cdot2\cdot3\cdot\ldots\cdot2\cdot25}=\frac{1\cdot2\cdot3\cdot\ldots\cdot50}{2^{25}\cdot\left(1\cdot2\cdot3\cdot\ldots\cdot25\right)}\)

\(=\frac{26\cdot27\cdot\ldots\cdot50}{2^{25}}=\frac{26}{2}\cdot\frac{27}{2}\cdot\ldots\cdot\frac{50}{2}\)

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

giúp mk với

so sanh -49/78

Trả lời:

\(a.\frac{27}{82}< \frac{26}{75}\)

\(b.\frac{-49}{78}< \frac{64}{-95}\)

***

Quy đồng ( đây ngu toán không logic )

a)\(\dfrac{3}{6};\dfrac{2}{6};\dfrac{4}{6}\Rightarrow\dfrac{4}{6}>\dfrac{3}{6}>\dfrac{2}{6}\)

b)\(\dfrac{16}{9};\dfrac{24}{13}=\dfrac{208}{117};\dfrac{216}{117}\Rightarrow\dfrac{216}{117}>\dfrac{208}{117}\)

c)(Trời ơi cái đề bài)

h)\(\dfrac{27}{82};\dfrac{26}{75}=\dfrac{2025}{6150};\dfrac{2132}{6150}\Rightarrow\dfrac{2025}{6150}< \dfrac{2132}{6150}\)

d)(Trời ơi giống câu c)

i)\(\dfrac{-49}{78};\dfrac{64}{-95}=\dfrac{-4655}{7410};\dfrac{4992}{7410}\Rightarrow\dfrac{-4655}{7410}< \dfrac{4992}{7410}\)

P/s : Tự kết luận mỗi câu

a,\(\dfrac{1}{2}=\dfrac{1.3}{2.3}=\dfrac{3}{6}\),\(\dfrac{1}{3}=\dfrac{1.2}{3.2}=\dfrac{2}{6}\),\(\dfrac{2}{3}=\dfrac{2.2}{3.2}=\dfrac{4}{6}\)

vì có mẫu chung là 6 nên ta so sánh tử\(\Rightarrow\)ta so sánh 3,2,4

vì 2<3<4\(\Rightarrow\)\(\dfrac{2}{6}< \dfrac{3}{6}< \dfrac{4}{6}\Rightarrow\dfrac{1}{3}< \dfrac{1}{2}< \dfrac{2}{3}\)

mk vẫn làm được nhưng bây giờ mk lazy qua nên mk nghỉ đây

bn tick cho mk nha

`M=(10^25+1)/(10^26+1)`

`=>10M=(10^26+10)/(10^26+1)=1+9/(10^26+1)``

`CMTT:10N=1+9/(10^27+1)`

Vì `1/(10^26+1)>1/(10^27+1)`

`=>9/(10^26+1)>9/(10^27+1)`

`=>1+9/(10^26+1)>1+9/(10^27+1)`

`=>10M>10N=>M>N`

c) \(\dfrac{27}{26}\)và\(\dfrac{38}{37}\)

Ta có: \(\dfrac{27}{26}=1+\dfrac{1}{26}\); \(\dfrac{38}{37}=1+\dfrac{1}{37}\)

Vì \(\dfrac{1}{26}>\dfrac{1}{37}\) nên \(\dfrac{27}{26}>\dfrac{38}{37}\)

c: \(\dfrac{27}{26}-1=\dfrac{1}{26}\)

\(\dfrac{38}{37}-1=\dfrac{1}{37}\)

mà \(\dfrac{1}{26}>\dfrac{1}{37}\)

nên \(\dfrac{27}{26}>\dfrac{38}{37}\)