Tính :
P = \(\frac{\frac{1}{19}+\frac{2}{18}+\frac{3}{17}+....+\frac{18}{2}+\frac{19}{1}}{\frac{1}{2}+\frac{1}{3}+...+\frac{1}{19}+\frac{1}{20}}\)
\(B=1+\frac{1}{1+2}+\frac{1}{1+2+3}+\frac{1}{1+2+3+4}+...+\frac{1}{1+2+...+19}\)
\(1+\frac{1}{1+2}+\frac{1}{1+2+3}+........+\frac{1}{1+2+3+....+19}=?\)
\(1+\frac{1}{1+2}+\frac{1}{1+2+3}+........+\frac{1}{1+2+3+...+19}\)
Tính: \(1+\frac{1}{1+2}+\frac{1}{1+2+3}+...+\frac{1}{1+2+3+...+19}=?\)
\(B=1+\frac{1}{1+2}+\frac{1}{1+2+3}+\frac{1}{1+2+3+4}+...+\frac{1}{1+2+...+19}\)
giúp hội trưởng ta với
Giải giúp mình bài này với.
\(1+\frac{1}{1+2}+\frac{1}{1+2+3}+\frac{1}{1+2+3+4}+...+\frac{1}{1+2+3+4+...+19}\)
giúp mình với:
\(\frac{1}{1+2+3+4}+\frac{1}{1+2+...+5}+\frac{1}{1+2+...+6}+...+\frac{1}{1+2+...+19}\)
Tính: A= \(1+\frac{1}{1+2}+\frac{1}{1+2+3}+...+\frac{1}{1+2+3+4+...+19}\).