`#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

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

\(\dfrac{11}{31}\) = \(\dfrac{11\times10}{31\times10}\) = \(\dfrac{110}{310}\) = 1 - \(\dfrac{200}{310}\) 

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

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

Nên \(\dfrac{11}{31}\)  < \(\dfrac{111}{311}\)

\(\dfrac{11}{31}=\dfrac{11x311}{31x311}=\dfrac{3421}{31x311}\)

\(\dfrac{111}{311}=\dfrac{111x31}{31x311}=\dfrac{3441}{31x311}\)

mà \(\dfrac{3421}{31x311}< \dfrac{3441}{31x311}\)

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

\(Cảmơncácbạn\)☺

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

27/31<2727/3131

11/31<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)\(S=\left(-11+91\right)+\left(92-12\right)+\left(93-13\right)\\ S=80+80+80=240\)

\(\)b)\(S=-111+223-123+111\\ S=\left(-111+111\right)+\left(223-123\right)\\ S=0+100=100\)

c)\(S=127-263-27+153\\ S=\left(127-27\right)-\left(263-153\right)\\ S=100-110=-10\)