`#3107.101107`

`a)`

Ta có:

\(\dfrac{2727}{3131}=\dfrac{2727\div27}{3131\div31}=\dfrac{27}{31}\)

Vì \(\dfrac{27}{31}=\dfrac{27}{31}\)

\(\Rightarrow\dfrac{27}{31}=\dfrac{2727}{3131}\)

`b)`

Ta có:

\(\dfrac{11}{31}=1-\dfrac{20}{31}=1-\dfrac{200}{310}\)

\(\dfrac{111}{311}=1-\dfrac{200}{311}\)

Vì \(\dfrac{200}{310}>\dfrac{200}{311}\)

\(\Rightarrow1-\dfrac{200}{310}< 1-\dfrac{200}{311}\)

\(\Rightarrow\dfrac{11}{31}< \dfrac{111}{311}.\)

27/31 = 2727/3131

11/31 bé hơn 111/311

27/31<2727/3131

11/31<111/311

\(a,\dfrac{2727}{3131}=\dfrac{2727:101}{3131:101}=\dfrac{27}{31}\\ Vậy:\dfrac{27}{31}=\dfrac{2727}{3131}\)

đề bài là gì

Ta có : $\frac{11}{31}=1-\frac{20}{31}=1-\frac{200}{310}$

           $\frac{111}{311}=1-\frac{200}{311}$

Vì $\frac{200}{310}>\frac{200}{311}$ nên $1-\frac{200}{310}<1-\frac{200}{311}$ hay $\frac{11}{31}<\frac{111}{311}$

Vậy , $\frac{11}{31}<\frac{111}{311}.$

\(\dfrac{11}{31}\) > \(\dfrac{111}{311}\)

a) 56 /55 và 2018/2019

Ta có 56/55 > 1 ; 2018/2019 < 1

Do đó nên 56/55 > 2018/2019

b) 15/17 và 9/11

Ta có 15/17 = 0,88...

          9/11   = 0,81...

Vì 0,88...> 0,81....

nên 15/17 > 9/11

c) 11/31 và 111 / 311

Ta có : 11/31 : 111/311 = 3421/3441

Vì 3421/3441 < 1

nên 11/31 < 111/311

d) 18/109 và 5/30

Ta có : 18/109 = 0,165....

            5/30     = 0,166...

Vì 0,165...< 0,166...

nên 18/109 < 5/30

a,\(\frac{56}{55}>1\)

\(\frac{2018}{2019}< 1\)

Do đó \(\frac{56}{55}>\frac{2018}{2019}\)

b,\(\frac{15}{17}=1-\frac{2}{17}\)

\(\frac{9}{11}=1-\frac{2}{11}\)

Ta có \(\frac{2}{11}>\frac{2}{17}\Rightarrow1-\frac{2}{11}< 1-\frac{2}{17}\Rightarrow\frac{15}{17}>\frac{9}{11}\)

c và d tương tự phần b

a, 56/55 > 2018/2019

b, 15/17 >9/11

c, 11/31 < 111/311

d , 18/109 < 5/30

a. \(\frac{56}{55}>1>\frac{2018}{2019}\)\(\Rightarrow\frac{56}{55}>\frac{2018}{2019}\)

b. \(\frac{15}{17}=1-\frac{2}{17}\)

   \(\frac{9}{11}=1-\frac{2}{11}\)

Vì \(\frac{2}{17}< \frac{2}{11}\)\(\Rightarrow1-\frac{2}{17}>1-\frac{2}{11}\)\(\Rightarrow\frac{15}{17}>\frac{9}{11}\)

c. \(\frac{11}{31}=1-\frac{20}{31}=1-\frac{200}{310}\)

  \(\frac{111}{311}=1-\frac{200}{311}\)

Vì \(\frac{200}{310}>\frac{200}{311}\)\(\Rightarrow1-\frac{200}{310}< 1-\frac{200}{311}\)\(\Rightarrow\frac{11}{31}< \frac{111}{311}\)

d. \(\frac{5}{30}=\frac{1}{6}=\frac{18}{108}>\frac{18}{109}\)\(\Rightarrow\frac{5}{30}>\frac{18}{109}\)

a,

Ta có:
\(\dfrac{3}{7}=1-\dfrac{4}{7}\)
\(\dfrac{11}{15}=1-\dfrac{4}{15}\)
So sánh phân số \(\dfrac{4}{7}\) và \(\dfrac{4}{15}\)
Vì \(7< 15\) nên \(\dfrac{1}{7}>\dfrac{1}{15}\)
\(\Rightarrow1-\dfrac{4}{7}< 1-\dfrac{4}{15}\)
Vậy \(\dfrac{3}{7}< \dfrac{11}{15}\)

b)

\(\dfrac{-11}{6}< -1< \dfrac{-8}{9}\) nên \(\dfrac{-11}{6}< \dfrac{-8}{9}\)

c) 

\(\dfrac{305}{25}=\dfrac{305:5}{25:5}=\dfrac{61}{5}\)
Ta có: 
Mẫu số chung 2 phân số: 80
\(\dfrac{297}{16}=\dfrac{297*5}{16*5}=\dfrac{1485}{80}\)
\(\dfrac{61}{5}=\dfrac{61*16}{5*16}=\dfrac{976}{80}\)
Vì \(1485>976\) nên\(\dfrac{1485}{80}>\dfrac{976}{80}\)
Vậy \(\dfrac{297}{16}>\dfrac{305}{25}\)

d,

$\frac{-205}{317}=\frac{-205:-1}{317:-1}=\frac{205}{-317}$
Ta có: 
Mẫu số chung 2 phân số: -35187
\(\dfrac{205}{-317}=\dfrac{205*111}{-317*111}=\dfrac{22755}{-35187}\)
\(\dfrac{-83}{111}=\dfrac{-83*-317}{111*-317}=\dfrac{26311}{-35187}\)
Vì \(22755< 26311\) nên\(\dfrac{22755}{-35187}< \dfrac{26311}{-35187}\)
Vậy \(\dfrac{-205}{317}< \dfrac{-83}{111}\)

Câu d, mình làm sai, cho mình sửa lại:

\(\dfrac{-205}{317}=\dfrac{-22755}{35187}\)

\(\dfrac{-83}{111}=\dfrac{-26311}{35187}\)

Vậy là  \(-22755>-26311\) hay \(\dfrac{-205}{317}>\dfrac{-83}{111}\)