Tìm x
a, (\(\frac{11}{1.3}\) + \(\frac{11}{3.5}\)+ ...... + \(\frac{11}{97.99}\)) . 2x = \(\frac{49}{9}\)
b, \(\frac{1}{1.4}\) + \(\frac{1}{4.7}\)+.......+ \(\frac{1}{97.100}\)= \(\frac{0,33.x}{2009}\)
c, (\(\frac{1}{3.8}\)+ \(\frac{1}{8.13}\)+ ........ + \(\frac{1}{103.108}\)) . 540 - 2x = 14
Tìm x biết:
\(\left(\frac{1}{1.4}+\frac{1}{4.7}+\frac{1}{7.10}+...+\frac{1}{97.100}\right)=\frac{0,33.x}{2009}\)
(\(\frac{1}{1.4}+\frac{1}{4.7}+\frac{1}{7.10}+..........+\frac{1}{97.100}=\frac{0.33.x}{2009}\))
Tìm x, biết:
a) 2x+ 2x+1 + 2x+2+ 2x+3 = 480
b) \(\frac{1}{1.4}+\frac{1}{4.7}+\frac{1}{7.10}+..................+\frac{1}{97.100}=\frac{0,33.x}{2009}\)
mk đang cần gấp
\(\frac{1}{1.4}+\frac{1}{4.7}+\frac{1}{7.10}+........+\frac{1}{97.100}=\frac{0.33..x}{2009}\)
giúp mik nhé
Tính:
a) \(\frac{2}{1.3}+\frac{2}{3.5}+\frac{2}{5.7}+...+\frac{2}{49.51}\)
b) \(\frac{3}{1.4}+\frac{3}{4.7}+\frac{3}{7.10}+...+\frac{3}{97.100}\)
Tìm x
\(\frac{1}{1.4}+\frac{1}{4.7}+\frac{1}{7.10}+...+\frac{1}{x\left(x+3\right)}=\frac{125}{376}\)VỚI X thuộc N*
\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+...+\frac{1}{x\left(2x+1\right)}=\frac{1}{10}\)VỚI X thuộc N*
\(\frac{1}{15}+\frac{1}{21}+\frac{1}{28}+\frac{1}{36}+...+\frac{2}{x\left(x+1\right)}=\frac{11}{40}\)VỚI X thuộc N*
\(S=\frac{1}{1.4}+\frac{1}{4.7}+\frac{1}{7.10}+...+\frac{1}{97.100}\)
Tính nhanh
\(A=\frac{1}{1.4}+\frac{1}{4.7}+\frac{1}{7.10}+\frac{1}{10.13}+...+\frac{1}{97.100}\)