\(-\frac{1}{5}< 0;\frac{1}{1000}>0=>-\frac{1}{5}< \frac{1}{1000}\)
\(\frac{1}{1000}\)lớn hơn đơn giản vì số dương đơn nhiên lớn hơn số âm -_-
Bài 4: Tính hợp lý
A=\(\frac{4}{\text{1⋅2}}+\frac{4}{\text{3⋅5}}+......+\frac{4}{\text{20⋅11⋅2013}}\)
Bài 5: So sánh với 1:
A=\(\frac{1}{\text{1⋅2}}+\frac{1}{\text{2⋅3}}+\frac{1}{\text{3⋅4}}+......+\frac{1}{\text{49⋅50}}\)
bai 1 \(\frac{-3}{\text{2}}+\frac{5}{7}+\frac{-31}{14}< hoac=\text{x}< \frac{1}{\text{2}}+\frac{1}{3}+\frac{1}{6}\)\(\frac{1}{6}\)
bai 2 \(\frac{\text{x}+4}{\text{x}-\text{2}}+\frac{\text{2}\text{x}-5}{\text{x}-\text{2}}\)la so nguyen
\(\frac{2017}{1\times2\text{×}3}+\frac{2017}{2\text{×}3\text{×}4}+\frac{2017}{3\text{×}4\text{×}5}+..+\frac{2017}{19\text{×}20\text{×}21}\)
So sánh :
A= \(\text{\frac{\text{1 + 7 + 7^2 +...+ 7^9}}{\text{1 + 7 + 7^2 +...+ 7^9}+\:7^{10}}}\)
B = \(\frac{1+5+5^{2+}...+5^9}{1+5+5^2+...+5^{10}}\)
Tính tổng : S= 2016 + \(\frac{20\text{1}6}{\text{1}+2}\) + \(\frac{20\text{1}6}{\text{1}+2+3}\) +....+ \(\frac{20\text{1}6}{\text{1}+2+3+...+20\text{1}5}\)
so sánh A=\(\frac{\text{ 10^7+ 2019}}{10^7-1}\) và B=\(\frac{\text{10^7 +2017}}{10^7-3}\)
So sánh với n thuộc N*
\(\frac{n+1}{n+2}v\text{à}\text{ }\frac{n}{n-3}\)
Cho A=\(\frac{1985\text{×}1987-1}{1980+1985\text{×}1986}\)
Hãy so sánh A với 1
Cho \(A=\frac{1}{5^2}+\frac{2}{5^3}+\frac{3}{5^4}+...+\frac{\text{n}}{5^{\text{n}-2}}+...+\frac{11}{5^{12}}\) với \(\text{n}\in\text{N }\).CMR:\(A< \frac{1}{16}\)
