Cho S = \(\dfrac{1}{2}\). \(\dfrac{3}{4}\). \(\dfrac{5}{6}\). ... . \(\dfrac{9999}{10000}\)so sánh S với 0,01
Cho \(C=\dfrac{3}{4}+\dfrac{8}{9}+\dfrac{15}{16}+...+\dfrac{9999}{10000}\) . Chứng minh rằng \(C>98\)
\(A=\dfrac{1}{2}+\dfrac{1}{6}+\dfrac{1}{12}+.....+\dfrac{1}{10000}\)
\(B=\dfrac{2}{1\cdot3}+\dfrac{2}{3\cdot5}+\dfrac{2}{5\cdot7}+....+\dfrac{2}{99\cdot101}\)
Cho :
\(A=\dfrac{5}{1.2.3}+\dfrac{8}{2.3.4}+\dfrac{11}{3.4.5}+...+\dfrac{6056}{2018.2019.2020}\)
Hãy so sánh A với 2
Cho tổng \(T=\dfrac{2}{2^1}+\dfrac{3}{2^2}+\dfrac{4}{2^3}+...+\dfrac{2020}{2^{2019}}+\dfrac{2021}{2^{2020}}\)
So sánh T với 3
CMR : \(\dfrac{2}{5}< A< \dfrac{8}{9}\)
Với \(A=\dfrac{1}{2^2}+\dfrac{1}{3^2}+\dfrac{1}{4^2}+\dfrac{1}{5^2}+\dfrac{1}{6^2}+\dfrac{1}{7^2}+\dfrac{1}{8^2}+\dfrac{1}{9^2}\)
So sánh A và B :
\(A=\dfrac{1}{3}+\dfrac{1}{3^2}+\dfrac{1}{3^3}+...+\dfrac{1}{3^{100}}\)
\(B=\dfrac{1}{2}\)
a) \(\dfrac{\left(3+\dfrac{1}{6}\right)-\dfrac{2}{5}}{\left(5-\dfrac{1}{6}\right)+\dfrac{7}{10}}\)
b) \(\dfrac{\left(4,08-\dfrac{2}{25}\right):\dfrac{4}{17}}{\left(6\dfrac{5}{9}-3\dfrac{1}{4}\right).2\dfrac{2}{7}}\)
c) \(\dfrac{2-\dfrac{1}{4}+\dfrac{1}{3}-\dfrac{3}{5}}{3-\dfrac{1}{5}-\dfrac{5}{3}}\)
Cho biểu thức
\(A=\dfrac{-10}{52}+\dfrac{-10}{140}+\dfrac{-10}{260}+...+\dfrac{-10}{140}\)
so sánh A với \(\dfrac{-1}{3}\)
Tính giá trị biểu thức
B=\(2013+\dfrac{2013}{1+2}+\dfrac{2013}{1+2+3}+\dfrac{2013}{1+2+3+4}+...+\dfrac{2013}{1+2+3+4+5}\)