So sánh:\(2017\times2018\times2019\)với\(2018^3\)
Những câu hỏi liên quan
So sánh: a)frac{-3}{100}và frac{2}{3} b)frac{267}{-268}vàfrac{-1347}{1343} c) frac{2017times2018-1}{2017times2018}vàfrac{2018times2019-1}{2018times2019} e)frac{2017times2018}{2017times2018+1}vàfrac{2018times2019}{2018times2019+1} Gải cách rút gọn cám ơn ạ
Đọc tiếp
So sánh: a)\(\frac{-3}{100}\)và \(\frac{2}{3}\) b)\(\frac{267}{-268}\)và\(\frac{-1347}{1343}\) c) \(\frac{2017\times2018-1}{2017\times2018}\)và\(\frac{2018\times2019-1}{2018\times2019}\) e)\(\frac{2017\times2018}{2017\times2018+1}\)và\(\frac{2018\times2019}{2018\times2019+1}\) Gải cách rút gọn cám ơn ạ
a) frac{-3}{100}vàfrac{2}{3} b)frac{267}{-268}vàfrac{-1347}{1343}c)frac{2017times2018-1}{2017times2018}vàfrac{2018times2019-1}{2018times2019}d)frac{2017times2018}{2017times2018+1}vàfrac{2018times2019}{2018times2019+1}
Đọc tiếp
a) \(\frac{-3}{100}\)và\(\frac{2}{3}\) b)\(\frac{267}{-268}\)và\(\frac{-1347}{1343}\)c)\(\frac{2017\times2018-1}{2017\times2018}\)và\(\frac{2018\times2019-1}{2018\times2019}\)d)\(\frac{2017\times2018}{2017\times2018+1}\)và\(\frac{2018\times2019}{2018\times2019+1}\)
a) Ta có : \(\frac{-3}{100}< 0< \frac{2}{3}\)
\(\Rightarrow\frac{-3}{100}< \frac{2}{3}\)
b) Ta có : \(\frac{267}{268}< 1< \frac{1347}{1343}\)
\(\Rightarrow\frac{267}{268}< \frac{1347}{1343}\)
\(\Rightarrow\frac{267}{-268}< \frac{-1347}{1343}\)
c) Ta có : \(\frac{2017.2018-1}{2017.2018}=\frac{2017.2018}{2017.2018}-\frac{1}{2017.2018}=1-\frac{1}{2017.2018}\)
\(\frac{2018.2019-1}{2018.2019}=\frac{2018.2019}{2018.2019}-\frac{1}{2018.2019}=1-\frac{1}{2018.2019}\)
mà \(2017.2018< 2018.2019\)
\(\Rightarrow\frac{1}{2017.2018}>\frac{1}{2018.2019}\)
\(\Rightarrow1-\frac{1}{2017.2018}< 1-\frac{1}{2018.2019}\)
\(\Rightarrow\frac{2017.2018-1}{2017.2018}< \frac{2018.2019-1}{2018.2019}\)
d) Ta có : \(\frac{2017.2018}{2017.2018+1}=\frac{2017.2018+1}{2017.2018+1}-\frac{1}{2017.2018+1}=1-\frac{1}{2017.2018+1}\)
\(\frac{2018.2019}{2018.2019+1}=\frac{2018.2019+1}{2018.2019+1}-\frac{1}{2018.2019+1}=1-\frac{1}{2018.2019+1}\)
mà \(2017.2018+1< 2018.2019+1\)
\(\Rightarrow\frac{1}{2017.2018+1}>\frac{1}{2018.2019+1}\)
\(\Rightarrow1-\frac{1}{2017.2018+1}< 1-\frac{1}{2018.2019+1}\)
\(\Rightarrow\frac{2017.2018}{2017.2018+1}< \frac{2018.2019}{2018.2019+1}\)
Tính nhanh:( giúp mik với )
a) \(2018^2-2017\times2019\)
b) \(\frac{2018^3+1}{2018-2017}\)
2017.2019 = (2018-1)(2018+1) = 20182 -1 => a =1
b= 20183 +1 (???)
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Cho A=2016/2017+2017/2018+2018/2019.
So sánh A với 3
\(A=\frac{2016}{2017}+\frac{2017}{2018}+\frac{2018}{2019}=\left(1-\frac{1}{2017}\right)+\left(1-\frac{1}{2018}\right)+\left(1-\frac{1}{2019}\right)\)
\(A=3-\left(\frac{1}{2017}+\frac{1}{2018}+\frac{1}{2019}\right)< 3\)
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Ta có :
2016/2017 < 1
2017/2018 < 1
2018/2019 < 1
Mà 2016/2017 + 2017/2018 + 2018/2019 < 1 + 1 + 1 = 3
Nên A < 3
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Cho A=2016/2017+2017/2018+2018/2019.
So sánh A với 3.
\(A=\frac{2016}{2017}+\frac{2017}{2018}+\frac{2018}{2019}\)
Ta có:
\(\frac{2016}{2017}< 1\)
\(\frac{2017}{2018}< 1\)
\(\frac{2018}{2019}< 1\)
\(\Rightarrow\frac{2016}{2017}+\frac{2017}{2018}+\frac{2018}{2019}< 1+1+1=3\)
\(\Rightarrow A< 3\)
Vậy \(A< 3\)
Tham khảo nhé
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\(\frac{2016}{2017}+\frac{2017}{2018}+\frac{2018}{2019}\)
\(=1-\frac{1}{2017}+1-\frac{1}{2018}+1-\frac{1}{2019}\)
\(=\left(1+1+1\right)-\left(\frac{1}{2017}+\frac{1}{2018}+\frac{1}{2019}\right)\)
\(=3-\left(\frac{1}{2017}+\frac{1}{2018}+\frac{1}{2019}\right)< 3\)
Vậy \(\frac{2016}{2017}+\frac{2017}{2018}+\frac{2018}{2019}< 3\left(đpcm\right)\)
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vì 2016/2017 < 1
2017/2018 < 1
2018/2019 < 1
Nên A= 2016/2017 + 2017/2018 + 2018/2019 < 1 + 1 + 1 = 3
Vậy A < 3.
Tk nha ♡♡
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2017/căn 2018+2018/căn 2017 so sánh với căn 2017 + căn 2018
Áp dụng BĐT Svác-xơ ta có:
\(\frac{2017}{\sqrt{2018}}+\frac{2018}{\sqrt{2017}}\ge\frac{\left(\sqrt{2017}+\sqrt{2018}\right)^2}{\sqrt{2017}+\sqrt{2018}}=\sqrt{2017}+\sqrt{2018}\)
do \(\frac{2017}{\sqrt{2018}}\ne\frac{2018}{\sqrt{2017}}\)nên dấu "=" không xảy ra
Vậy \(\frac{2017}{\sqrt{2018}}+\frac{2018}{\sqrt{2017}}>\sqrt{2017}+\sqrt{2018}\)
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so sánh: A= 2017+2018/2018+2019 với B= 2017/2018+2018/2019
Cho A= \(\frac{2017^{2018}+1}{2017^{2018}-3}\)
B= \(\frac{2017^{2018}-1}{2017^{2018}-5}\)
Hãy so sánh A với B
So sánh:
A= 2018^2017+1/2018^2017-1
B= 2018^2017-1/2018^2017-3
link nà:https://olm.vn/hoi-dap/tim-kiem?q=so+s%C3%A1nh+:+A=2017%5E2017/2018%5E2017+1B=2017%5E2016+1/2017%5E2017+1+&id=862033
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