Các câu hỏi tương tự
Tính \(Q=1\cdot100+2\cdot99+3\cdot98+4\cdot97+.....+98\cdot3+99\cdot2+100\cdot1\)
Tính : S = \(1+1\cdot1!+2\cdot2!+3\cdot3!+....+100\cdot100!\)
Tính: \(B=\frac{100^2+1^2}{100\cdot1}+\frac{99^2+2^2}{99\cdot2}+\frac{98^2+3^2}{98\cdot3}+...+\frac{52^2+49^2}{52\cdot49}+\frac{51^2+50^2}{51\cdot50}\)
\(A=\frac{4}{10\cdot2}+\frac{6}{2\cdot20}+\frac{15}{5\cdot20}+\frac{5}{5\cdot40};B=\frac{3}{1\cdot5}+\frac{5}{13\cdot1}+\frac{11}{13\cdot3}+\frac{2}{3\cdot26}\)
So sánh A với B
CM :\(\frac{1\cdot2-1}{2!}+\frac{2\cdot3-1}{3!}+\frac{3\cdot4-1}{4!}+...+\frac{99\cdot100-1}{100!}<2\)
\(\frac{1\cdot98+2\cdot97+3\cdot96+...+98\cdot1}{1\cdot2+2\cdot3+3\cdot4+...+98\cdot99}\)
Tígiasgias trị biểu thức :
\(A=\frac{1\cdot2004+2\cdot2003+3\cdot2002+...+2004\cdot1}{1\cdot2+2\cdot3+3\cdot4+...+2004\cdot2005}\)
TÍNH : \(\frac{1\cdot2016+2\cdot2015+...+2015\cdot2+2016\cdot1}{1\cdot2+2\cdot3+...+2016\cdot2017}\)
\(A=\frac{1}{1\cdot2}+\frac{1}{2\cdot3}+\frac{1}{3\cdot4}+...+\frac{1}{99\cdot100}\)