Question

So sánh các phân số sau:

  a, \(\frac{13}{7}\)và  \(\frac{21}{12}\)

  b, \(\frac{2018}{2019}\)và  \(\frac{2019}{2020}\)

  c, \(\frac{17}{53}\)và  \(\frac{19}{50}\)

                                                              LÀM HỘ MK NHA MỌI NGƯỜI

 

Answer 1

ta có

\(1-\frac{2018}{2019}=\frac{1}{2019}\)và\(1-\frac{2019}{2020}=\frac{1}{2020}\)

vì\(\frac{1}{2019}>\frac{1}{2020}\)vậy\(\frac{2018}{2019}>\frac{2019}{2020}\)

Answer 2

a) Ta có \(\frac{13}{7}=2-\frac{1}{7}\)

              \(\frac{21}{12}=2-\frac{1}{4}\)

Vì \(\frac{1}{7}< \frac{1}{4}\)\(\Rightarrow2-\frac{1}{7}>2-\frac{1}{4}\)\(\Rightarrow\frac{13}{7}>\frac{21}{12}\)

Vậy \(\frac{13}{7}>\frac{21}{12}\)

b) Ta có : \(\frac{2018}{2019}=1-\frac{1}{2019}\)

               \(\frac{2019}{2020}=1-\frac{1}{2020}\)

Vì \(\frac{1}{2019}>\frac{1}{2020}\Rightarrow1-\frac{1}{2019}< 1-\frac{1}{2020}\Rightarrow\frac{2018}{2019}< \frac{2019}{2020}\)

Vậy \(\frac{2018}{2019}< \frac{2019}{2020}\)

c) Ta có :Vì  \(\frac{17}{53}< \frac{17}{50}< \frac{19}{50}\) \(\Rightarrow\frac{17}{53}< \frac{19}{50}\)

Vậy \(\frac{17}{53}< \frac{19}{50}\)