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22 tháng 8 2021

a ) <

b ) <

-2021/2020<1/2

15 tháng 4 2023

A = \(\dfrac{2020}{2021}\) + \(\dfrac{2021}{2022}\) ;  B = \(\dfrac{2020+2021}{2021+2022}\)

B = \(\dfrac{2020+2021}{2021+2022}\)   = \(\dfrac{2020}{2021+2022}\) + \(\dfrac{2021}{2021+2022}\)

\(\dfrac{2020}{2021}\)   > \(\dfrac{2020}{2021+2022}\)

\(\dfrac{2021}{2022}\)     > \(\dfrac{2021}{2021+2022}\)

Cộng vế với vế ta có:

A = \(\dfrac{2020}{2021}\) + \(\dfrac{2021}{2022}\) > \(\dfrac{2020}{2021+2022}\) + \(\dfrac{2021}{2021+2022}\) = B

Vậy A > B

 

15 tháng 4 2023

A =  \(\dfrac{10^{10}-1}{10^{11}-1}\) 

\(\times\) 10 = \(\dfrac{(10^{10}-1)\times10}{10^{11}-1}\) = \(\dfrac{10^{11}-10}{10^{11}-1}\) = 1 - \(\dfrac{9}{10^{11}-1}\) < 1

B = \(\dfrac{10^{10}+1}{10^{11}+1}\)

\(\times\) 10 = \(\dfrac{(10^{10}+1)\times10}{10^{11}+1}\)  = \(\dfrac{10^{11}+10}{10^{11}+1}\) = 1 + \(\dfrac{9}{10^{11}+1}\) > 1

Vì 10 A< 1< 10B

Vậy A < B

 

Tham khảo:

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DT
3 tháng 12 2023

\(2021\left(2020+2022\right)-2020\left(2021+2022\right)\\ =2021.2020+2021.2022-2020.2021-2020.2022\\ =\left(2021.2020-2020.2021\right)+\left(2021.2022-2020.2022\right)\\ =0+2022.\left(2021-2020\right)\\ =0+2022.1=2022\)

2020/2021<1

2021/2022<1

2022/2023<1

2023/2020=1+1/2020+1/2020+1/2020>1+1/2021+1/2022+1/2023

=>B>2020/2021+2021/2022+2022/2023+1/2021+1/2022+1/2023+1=4

26 tháng 9 2021

Ta có: \(B=2020.2021.2022=\left(2021-1\right).\left(2021+1\right).2021=\left(2021-1\right)^2.2021< 2021^2.2021=A\)

4 tháng 3 2022

Đây dang lớp mấy vây

17 tháng 1 2022

\(\dfrac{2021}{2022}=\dfrac{2020}{2021}\)

17 tháng 1 2022

\(\dfrac{2021}{2022}\) và \(\dfrac{2020}{2021}\)

\(\dfrac{2021}{2022}=1-\dfrac{1}{2022}\)

\(\dfrac{2020}{2021}=1-\dfrac{1}{2021}\)

\(\text{Vì }\)\(\dfrac{1}{2022}>\dfrac{1}{2021}=>1-\dfrac{1}{2022}>1-\dfrac{1}{2021}=>\dfrac{2021}{2022}>\dfrac{2020}{2021}\)