Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(A=\frac{2018^{2019}+1}{2018^{2019}-2017}=\frac{2018^{2019}-2017+2018}{2018^{2019}-2017}=\frac{2018^{2019}-2017}{2018^{2019}-2017}+\frac{2018}{2018^{2019}-2017}=1+\frac{2018}{2018^{2019}-2017}\)\(B=\frac{2018^{2019}+2}{2018^{2019}-2016}=\frac{2018^{2019}-2016+2018}{2018^{2019}-2016}=\frac{2018^{2019}-2016}{2018^{2019}-2016}+\frac{2018}{2018^{2019}-2016}=1+\frac{2018}{2018^{2019}-2016}\)Ta có: \(2018^{2019}-2017< 2018^{2019}-2016\)
\(\Rightarrow\frac{2018}{2018^{2019}-2017}>\frac{2018}{2018^{2019}-2016}\)
\(\Rightarrow1+\frac{2018}{2018^{2019}-2017}>1+\frac{2018}{2018^{2019}-2016}\)
\(\Rightarrow A>B\)
Vậy...
Ta có :
\(A=\frac{2018^{2019}+1}{2018^{2019}-2017}=\frac{2018^{2019}-2017+2018}{2018^{2019}-2017}=1+\frac{2018}{2018^{2019}-2017}\)
\(B=\frac{2018^{2019}+2}{2018^{2019}-2016}=\frac{2018^{2019}-2016+2018}{2018^{2019}-2016}=1+\frac{2018}{2018^{2019}-2016}\)
Vì \(2018^{2019}-2017< 2018^{2019}-2016\)nên \(\frac{2018}{2018^{2019}-2017}>\frac{2018}{2018^{2019}-2016}\)hay \(A>B\)
~ Hok tốt ~
\(C=5^{2018}+\frac{1}{5^{2017}+1}=\left(5^{2017}+1\right)+\frac{1}{5^{2017}+1}\)
\(D=5^{2018}+\frac{1}{5^{2018}+1}=\left(5^{2017}+1\right)+\left(1+\frac{1}{5^{2017}+2}\right)\)
Do \(\frac{1}{5^{2017}+1}< 1+\frac{1}{5^{2017}+2}\)
Nên \(C< D\)
Ta có : C = \(\frac{5^{2018}+1}{5^{2017}+1}\)
=> \(\frac{C}{5}=\frac{5^{2018}+1}{5^{2018}+5}=1-\frac{4}{5^{2018}+5}\)
Lại có D = \(\frac{5^{2019}+1}{5^{2018}+1}\)
=> \(\frac{D}{5}=\frac{5^{2019}+1}{5^{2019}+5}=1-\frac{4}{5^{2019}+5}\)
Vì \(\frac{4}{5^{2018}+5}>\frac{4}{5^{2019}+5}\Rightarrow1-\frac{4}{5^{2018}+5}< 1-\frac{4}{5^{2019}+5}\Rightarrow\frac{C}{5}< \frac{D}{5}\Rightarrow C< D\)
\(2018^{2019}-2018^{2018}=2018^{2018}.2018-2018^{2018}=2018^{2018}\left(2018-1\right)\)
\(2018^{2018}-2018^{2017}=2018^{2017}.2018-2018^{2017}=2018^{2017}\left(2018-1\right)\)
\(2018^{2019}-2018^{2018}>2018^{2018}-2018^{2017}\)
20182018 - 20182017= 20182019 - 20182018: Vì
20182018- 20182017 = 20181 và 20182019 - 20182018 = 20181
Do vậy : 20181 = 20181
Ta thấy :
\(\dfrac{2017^5}{2018^6}< \dfrac{2017^6}{2018^6}< \dfrac{2017^6}{2018^5}\Rightarrow\dfrac{2017^5}{2018^6}< \dfrac{2017^6}{2018^5}\)