TÍNH:
a, \(\frac{1}{10}-\frac{1}{40}-\frac{1}{88}-\frac{1}{154}-\frac{1}{238}-\frac{1}{340}\)
Tính:
\(\frac{1}{10}\) -\(\frac{1}{40}\)-\(\frac{1}{88}\)-\(\frac{1}{154}\)-\(\frac{1}{238}\)-\(\frac{1}{340}\)
Tìm x
\(\frac{1}{10}+\frac{1}{40}+\frac{1}{88}+...+\frac{1}{\left(3x+2\right).\left(3x+5\right)}=\frac{4}{25}\)
Tính: \(-1-\frac{1}{2}-\frac{1}{4}-\frac{1}{8}-\frac{1}{16}-...-\frac{1}{1024}\)
Chứng minh
\(\frac{118}{78}< \frac{1}{10}+\frac{1}{11}+\frac{1}{12}+...+\frac{1}{49}< \frac{118}{49}\)
a) Tính A=1/10+1/40+1/88+1/154+1/238+1/340
b) so sánh: 200410 + 20049 và 200510
\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{2}{x\left(x+1\right)}=\frac{998}{1000}\)
tìm x nhé
Tính :
M=\((\frac{0,4-\frac{2}{9}+\frac{2}{11}}{1,4-\frac{7}{9}+\frac{7}{11}}-\frac{\frac{1}{3}-0,25+\frac{1}{5}}{1\frac{1}{6}-0,875+0,7})\div\frac{2014}{2015}\)
Tinh nhanh
(\(\frac{1}{49}\)-\(\frac{1}{2^2}\)) . ( \(\frac{1}{49}\) - \(\frac{1}{3^2}\))........ ( \(\frac{1}{49}\) -\(\frac{1}{40^2}\))
