so sánh: 2020/2019 và -1234/-1235
Những câu hỏi liên quan
So sánh:
1234×1235-1/1234×1235 và 1235×1236-1/1235×1236
28 tháng 6 2021 lúc 15:55
So sánh A và B
A = \(\left(2020^{2019}+2019^{2019}\right)^{2020}\)
B = \(\left(2020^{2020}+2019^{2020}\right)^{2019}\)
Ta có: \(A=\left(2020^{2019}+2019^{2019}\right)^{2020}\)
\(=\left(2019^{2019}+2020^{2019}\right)^{2019}\cdot\left(2019^{2019}+2020^{2019}\right)\)
\(\Leftrightarrow\dfrac{A}{B}=\dfrac{\left(2019^{2019}+2020^{2019}\right)^{2019}\cdot\left(2019^{2019}+2020^{2019}\right)}{\left(2020^{2020}+2019^{2020}\right)^{2019}}\)
\(\Leftrightarrow\dfrac{A}{B}=\dfrac{2019^{2019}+2020^{2019}}{2019+2020}>1\)
\(\Leftrightarrow A>B\)
Đúng 1
Bình luận (0)
so sánh A=(19^2019+20^2019)^2020 và B =(19^2020+20^2020)^2019
17 tháng 4 2021 lúc 17:53
So sánh M = \(\dfrac{2019}{2020}+\dfrac{2020}{2021}\) và N = \(\dfrac{2019+2020}{2020+2021}\)
Giải:
Ta có: N=2019+2020/2020+2021
=>N=2019/2020+2021 + 2020/2020+2021
Vì 2019/2020 > 2019/2020+2021 ; 2020/2021 > 2020/2020+2021
=>M>N
Vậy ...
Chúc bạn học tốt!
Đúng 1
Bình luận (0)
Ta có : \(\dfrac{2019}{2020}>\dfrac{2019}{2020+2021}\)
\(\dfrac{2020}{2021}>\dfrac{2020}{2020+2021}\)
\(\Rightarrow\dfrac{2019}{2020}+\dfrac{2020}{2021}>\dfrac{2019+2020}{2020+2021}\)
\(\Rightarrow M>N\)
Đúng 1
Bình luận (0)
so sánh P=2019/2020+2020/2021+2021/2022 và Q=2019+2020+2021/2020+2021+2022
so sánh: A=2019^2019+1/2019^2020+1 và B=2019^2020+1/2019^2021+1
Vì 2019 + 2020 < 2019 + 2021 nên A < B
So sánh hai phân số
A=2017/2018+2018/2019+2019/2020 và B=(2017+2018+2019)/(2018+2019+2020)
So sánh x = 20192020 + 1 / 20192019 + 1 và y = 20192019 + 2020 / 20192018 + 2020
\(x=\frac{2019^{2020}+1}{2019^{2019}+1}>\frac{2019^{2020}+1+2018}{2019^{2019}+1+2018}=\frac{2019^{2020}+2019}{2019^{2019}+2019}=\frac{2019\left(2019^{2019}+1\right)}{2019\left(2019^{2018}+1\right)}=\frac{2019^{2019}+1}{2019^{2018}+1}\)(1)
\(y=\frac{2019^{2019}+2020}{2019^{2018}+2020}< \frac{2019^{2019}+2020-2019}{2019^{2018}+2020-2019}=\frac{2019^{2019}+1}{2019^{2018}+1}\left(2\right)\)
Từ (1) và (2) \(\Rightarrow x>y\)
so sánh: -2019/2019 và -2021/2020
\(\dfrac{-2019}{2019}=-1\)
\(\dfrac{-2021}{2020}=-1,004\)
\(\Rightarrow\dfrac{-2019}{2019}>\dfrac{-2021}{2020}\)
Đúng 0
Bình luận (1)
\(-\dfrac{2019}{2019}=-1\)
\(\dfrac{-2021}{2020}< -1\)
Do đó: \(-\dfrac{2019}{2019}>\dfrac{-2021}{2020}\)
Đúng 0
Bình luận (1)
2019 x 2020 - 1/ 2019 x 2020 và 2020 x 2021 - 1/ 2020 x 2021
so sánh phân số