So sánh hai phân số A=10^2022+1/10^2023+1;B=10^2021+1/10^2022+1
So sánh hai phân số: A = 10^2021 + 1 / 10^2022 + 1 B = 10^2022 + 1 / 10^2023 + 1
So sánh A=10^2024+1/10^2023+1 và B=10^2023+1=10^2022+1
\(A=\dfrac{10^{2024}+1}{10^{2023}+1}=\dfrac{10\left(10^{2023}+1\right)}{10^{2023}+1}-\dfrac{9}{10^{2023}+1}=1-\dfrac{9}{10^{2023}+1}\)
\(B=\dfrac{10^{2023}+1}{10^{2022}+1}=\dfrac{10\left(10^{2022}+1\right)}{10^{2022}+1}-\dfrac{9}{10^{2022}+1}=1-\dfrac{9}{10^{2022}+1}\)
Vì \(\dfrac{9}{10^{2023}+1}< \dfrac{9}{10^{2022}+1}\)
\(\Rightarrow A>B\)
so sánh: M=10^2021 + 1/10^2022 + 1
N=10^2022 + 1/10^2023 + 1
\(M=\dfrac{10^{2021}+1}{10^{2022}+1}\)
\(N=\dfrac{10^{2022}+1}{10^{2023}+1}< \dfrac{10^{2022}+1+9}{10^{2023}+1+9}=\dfrac{10^{2022}+10}{10^{2023}+10}=\dfrac{10\left(10^{2021}+1\right)}{10\left(10^{2022}+1\right)}\)
\(=\dfrac{10^{2021}+1}{10^{2022}+1}=M\)
Vậy \(M>N\)
so sánh
\(\dfrac{10^{2023}-3}{10^{2024}-3}\)
và
\(\dfrac{10^{2022}+1}{10^{2023}+1}\)
Ta có :
\(\dfrac{10^{2023}}{10^{2024}}=\dfrac{10^{2022}}{10^{2023}}\)
mà \(\dfrac{10^{2023}}{10^{2024}}>\dfrac{10^{2023}-3}{10^{2024}-3}\)
\(\dfrac{10^{2022}}{10^{2023}}< \dfrac{10^{2022}+1}{10^{2023}+1}\)
\(\Rightarrow\dfrac{10^{2023}-3}{10^{2024}-3}< \dfrac{10^{2022}+1}{10^{2023}+1}\)
M=$\frac{2022^{10}+1}{2023^{10}+1}$
N=$\frac{2023^{10}+1}{2024^{10}+1}$
so sánh M và N
So sánh hai phân số
\(A=\dfrac{10^{2021}+1}{10^{2022}+1}\)
2. không tính kết quả, hay so sánh:
b) M= \(\dfrac{10^{2023}+1}{10^{2024}+1}\) và N= \(\dfrac{10^{2022}+1}{10^{2023}+1}\)
b) \(M=\dfrac{10^{2023}+1}{10^{2024}+1}< 1\) ( Vì tử < mẫu )
Ta có: \(M=\dfrac{10^{2023}+1}{10^{2024}+1}< \dfrac{10^{2023}+1+9}{10^{2024}+1+9}=\dfrac{10^{2023}+10}{10^{2024}+10}=\dfrac{10.\left(10^{2022}+1\right)}{10.\left(10^{2023}+1\right)}=\dfrac{10^{2022}+1}{10^{2023}+1}=N\)
Vì \(\dfrac{10^{2023}+1}{10^{2024}+1}< \dfrac{10^{2022}+1}{10^{2023}+1}\) nên \(M< N\)
So sánh A= \(\dfrac{10^{2023}+5}{10^{2022}+5}\) và B= \(\dfrac{10^{2022}+5}{10^{2022}+5}\)
A và B có phần mẫu số bằng nhau mà tử A có 10^2023 lớn hơn B có 10^2022 => A > B
10^2023>10^2022
=>10^2023+5>10^2022+5
=>A>B
So sánh A= \(\dfrac{10^{2023}+5}{10^{2022}+5}\) và B=\(\dfrac{10^{2022}+5}{10^{2021}+5}\)
\(\dfrac{1}{10}A=\dfrac{10^{2023}+5}{10^{2023}+50}=1-\dfrac{45}{10^{2023}+50}\)
\(\dfrac{1}{10}B=\dfrac{10^{2022}+5}{10^{2022}+50}=1-\dfrac{45}{10^{2022}+50}\)
10^2023+50>10^2022+50
=>-45/10^2023+50<-45/10^2020+50
=>1/10A<1/10B
=>A<B