a)\(\frac{192}{195}>\frac{87}{89}\)

b)\(\frac{2018}{2015}< \frac{195}{192}\)

Chị chỉ em cách làm mà ko quy đồng ạ

\(\frac{192}{195}\)\(=1-\frac{3}{195}\)\(=1-\frac{1}{65}\)\(=1-\frac{2}{130}\)

\(\frac{87}{89}\)\(=1-\frac{2}{89}\)

\(1-\frac{2}{130}\)\(>1-\frac{2}{89}\)

\(=>\frac{192}{195}\)\(>\frac{87}{89}\)

\(\frac{192}{195}>\frac{87}{89}\)

ko cần quy đồng lấy tử chia mẫu rồi so sánh là được

\(\frac{43}{45}>\frac{43}{49}>\frac{27}{49}\)

38/8<17/49

38/8 > 17/49

k cho minh nha

chuc ban hoc tot

So sánh giữa 2000/2001 và 2001/2002

1 - 2000/2001 = 1/2001

1- 2001/2002 = 1/2002

Vì 1/2001 > 1/2002 nên 2000/2001 > 2001/2002

ta có:

1-\(\frac{2000}{2001}\)=\(\frac{2001}{2001}\)-\(\frac{2000}{2001}\)=\(\frac{1}{2002}\)

và 1- \(\frac{2001}{2002}\)=\(\frac{2002}{2002}\)-\(\frac{2001}{2002}\)=\(\frac{1}{2002}\)

vì \(\frac{1}{2001}\)> \(\frac{1}{2002}\)nên\(\frac{2000}{2001}\)<\(\frac{2001}{2002}\)

Ta có 1-2000/2001=1/2001

         1-2001/2002=1/2002

Mà 1/2001>1/2002

  =>2000/2001<2001/2002

Ta có 1-2000/2001=1/2001

         1-2001/2002=1/2002

Mà 1/2001>1/2002

  =>2000/2001<2001/2002

Ta có 15/31<15/30=1/2=83/166<83/99

3/3889 < 8/88889

\(\frac{3}{3889}=0.00071...\)

\(\frac{8}{88889}=8.999..\)

\(ví:0.00071...<08.999...\)

\(\Leftrightarrow\frac{3}{3889}<\frac{8}{88889}\)

Ta có : \(\frac{47}{15}:\frac{65}{21}=\frac{329}{325}\)mà \(\frac{329}{325}>1\)=>\(\frac{47}{15}>\frac{65}{21}\)