so sánh :
\(\frac{46872}{165564}\) và \(\frac{688882}{2422198}\)
Help me!!!!!!!!!!!!!!!!!!!!
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Vì :
+) 68888/2422198 < 68888/275552 = 1/4
+) 46872/187488 = 1/4 < 46872/165564
=> 68888/2422198 < 46872/165564
\(\frac{68888}{2422198}\) < \(\frac{68888}{275552}\)=\(\frac{1}{4}\)=\(\frac{46872}{187488}\)<\(\frac{46872}{165564}\)nên\(\frac{68888}{2422198}\)<\(\frac{46872}{165564}\)
\(\frac{-2367}{3457214}\)và\(\frac{3457214}{2367}\)
Vì\(\frac{-2367}{3457214}< 0;\frac{3457214}{2367}>0\)
Nên\(\frac{-2367}{3457214}< \frac{3457214}{2367}\)
\(\frac{-2367}{3457214}\)và \(\frac{3457214}{2367}\)
Vì \(\frac{-2367}{3457214}< 0;\frac{347214}{2367}>0\)
Nên \(\frac{-2367}{3457214}< \frac{3457214}{2367}\)
giải:
Ta có:
\(A=\frac{-9}{10^{2010}}+\frac{-19}{10^{2011}}=\frac{-9}{10^{2010}}+\frac{-9-10}{10^{2011}}=\frac{-9}{10^{2010}}+\frac{-9}{10^{2011}}+\frac{-10}{10^{2011}}\)
\(B=\frac{-9}{10^{2011}}+\frac{-19}{10^{2010}}=\frac{-9}{10^{2011}}+\frac{-9-10}{10^{2010}}=\frac{-9}{10^{2011}}+\frac{-9}{10^{2010}}+\frac{-10}{10^{2010}}\)
Vì \(\frac{10}{10^{2011}}< \frac{10}{10^{2010}}\rightarrow\frac{-10}{10^{2011}}>\frac{-10}{10^{2010}}\Rightarrow\frac{-9}{10^{2010}}+\frac{-9}{10^{2011}}+\frac{-10}{10^{2011}}>\frac{-9}{10^{2011}}+\frac{-9}{10^{2010}}+\frac{-10}{10^{2010}}\)
Vậy \(A>B\)( Bạn nhớ đọc kĩ lời giải nhé)
\(\frac{18}{91}\)\(\frac{23}{114}\) MSC :10374
\(\frac{18\cdot114}{91\cdot114}=\frac{1052}{10374}\)
\(\frac{23\cdot91}{114\cdot91}=\frac{2093}{10374}\)
\(\frac{18}{91}< \frac{23}{114}\)
HOK TỐT .
18/91 < 18/90 = 1/5 = 23/115 < 23/114
=> 18/91 < 23/114
Vậy 18/91 < 23/114
Ta có : \(A=\frac{1}{2^2}+\frac{1}{4^2}+\frac{1}{6^2}+...+\frac{1}{\left(2n\right)^2}\)
\(=\frac{1}{2^2}.\left(1+\frac{1}{2^2}+\frac{1}{3^2}+...+\frac{1}{n^2}\right)\)
\(< \frac{1}{4}.\left(1+\frac{1}{1.2}+\frac{1}{2.3}+....+\frac{1}{\left(n-1\right)n}\right)\)
\(=\frac{1}{4}.\left(1+1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{n-1}-\frac{1}{n}\right)\)
\(=\frac{1}{4}.\left(2-\frac{1}{n}\right)\)
\(=\frac{1}{2}-\frac{1}{4n}< 1\)
Vậy A < 1
\(A=\frac{1}{2^2}+\frac{1}{4^2}+\frac{1}{6^2}+...+\frac{1}{\left(2n\right)^2}.\)
\(A=\frac{1}{4}+\frac{1}{16}+\frac{1}{36}+...+\frac{1}{4n^2}.\)
\(A=\frac{1}{4}\left(1+\frac{1}{4}+\frac{1}{9}+...+\frac{1}{n^2}\right)\)
\(A=\frac{1}{4}\left(1+\frac{1}{2^2}+\frac{1}{3^2}+...+\frac{1}{n^2}\right)\)
So sánh \(\frac{1}{2^2}< \frac{1}{1\cdot2};\frac{1}{3^2}< \frac{1}{2\cdot3};....\)
\(\Rightarrow A< \frac{1}{4}\left(1+\frac{1}{1\cdot2}+\frac{1}{2\cdot3}+...+\frac{1}{n\left(n-1\right)}\right)\)
\(\Rightarrow A< \frac{1}{4}\left(1+1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-...-\frac{1}{n-1}+\frac{1}{n-1}-\frac{1}{n}\right)\)
\(\Rightarrow A< \frac{1}{4}\left(1+1-\frac{1}{n}\right)\)
\(\Rightarrow A< \frac{1}{4}\left(2-\frac{1}{n}\right)\)
\(\Rightarrow A< \frac{1}{2}-\frac{1}{4n}\)
có \(\frac{1}{2}>\frac{1}{2}-\frac{1}{4n}\)
\(\Rightarrow A< \frac{1}{2}-\frac{1}{4n}< \frac{1}{2}\) mà \(\frac{1}{2}< 1\)
\(\Rightarrow A< 1\)
Ta có :
\(A=\frac{2016^{2016}+2}{2016^{2016}-1}=\frac{\left(2016^{2016}-1\right)+3}{2016^{2016}-1}=1+\frac{3}{2016^{2016}-1}\)
\(B=\frac{2016^{2016}}{2016^{2016}-3}=\frac{\left(2016^{2016}-3\right)+3}{2016^{2016}-3}=1+\frac{3}{2016^{2016}-3}\)
Vì \(2016^{2016}-1>2016^{2016}-3\) nên \(\frac{3}{2016^{2016}-1}< \frac{3}{2016^{2016}-3}\)
\(\Rightarrow1+\frac{3}{2016^{2016}-1}< 1+\frac{3}{2016^{2016}-3}\)
\(\Rightarrow A< B\)
\(\frac{2323}{2424}=\frac{23.101}{24.101}=\frac{23}{24}\)
\(\frac{20132013}{20142014}=\frac{2013.10001}{2014.10001}=\frac{2013}{2014}\)
Ta có:
\(1-\frac{23}{24}=\frac{24}{24}-\frac{23}{24}=\frac{1}{24}\)
\(1-\frac{2013}{2014}=\frac{2014}{2014}-\frac{2013}{2014}=\frac{1}{2014}\)
Vì \(\frac{1}{24}>\frac{1}{2014}\) nên \(\frac{23}{24}< \frac{2013}{2014}\)
Vậy \(\frac{2323}{2424}< \frac{20132013}{20142014}\)
Tính phần bù với 1 nhé
mình cũng trình bày giống bạn "Muôn cảm súc"
\(\frac{46872}{165564}=\frac{62}{219}\)
\(\frac{688882}{2422198}=\frac{62}{218}\)
Do\(\frac{62}{219}\)bé-hơn\(\frac{62}{218}\)nên\(\frac{46872}{165564}\)bé-hơn\(\frac{688882}{2422198}\)
Tối giản: \(\frac{68888}{2422198}\)thành\(\frac{31}{109}\)và \(\frac{46872}{165564}\)thành \(\frac{62}{219}\)
Ta có:
\(\frac{31}{109}=\frac{31.219}{109.219}=\frac{6789}{23871}\)
\(\frac{62}{219}=\frac{62.109}{219.109}=\frac{6758}{23871}\)
Vì 6789 > 6758 nên \(\frac{46872}{165564}>\frac{688882}{2422198}\)
~ Hok tốt ~