\(\dfrac{1}{2.3}+\dfrac{1}{3.4}+\dfrac{1}{4.5}+...+\dfrac{1}{x}+\dfrac{1}{x+1}=\)\(\dfrac{2001}{4006}\)
\(\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{4}+...+\dfrac{1}{x}-\dfrac{1}{x+1}=\dfrac{2001}{4006}\)
\(\dfrac{1}{2}-\dfrac{1}{x+1}\) \(=\dfrac{1}{2}-\dfrac{2001}{4006}\)
\(\dfrac{1}{x+1}\) \(=\dfrac{1}{2003}\)
⇔ \(x+1=2003\)
\(x\) \(=2003-1\)
\(x\) \(=2002\)
Tìm x, biết:
a) x+\(\dfrac{1}{6}\)=\(\dfrac{-3}{8}\) b) \(2-\left(\dfrac{3}{4}-x\right)=\dfrac{7}{12}\)
c) \(\dfrac{1}{2}x\)+\(\dfrac{1}{8}x=\dfrac{3}{4}\) d) 75%-\(1\dfrac{1}{2}+0,5:\dfrac{5}{12}-\left(\dfrac{-1}{2}\right)^2\)
tìm x
\(\dfrac{3-x}{5-x}=\dfrac{6}{11}\) \(\left(1\dfrac{1}{3}-25\%.x-\dfrac{5}{12}\right)-2x=1,6:\dfrac{3}{5}\)
\(\dfrac{1}{2}.\left(x-\dfrac{2}{3}\right)-\dfrac{1}{3}.\left(2x-3\right)=x\)
\(2.\left(\dfrac{1}{2}-x\right)-3\left(x-\dfrac{1}{3}\right)=\dfrac{7}{2}\)
Tìm x biết: a) \(\left(x-\dfrac{1}{2}\right)\left(-3-\dfrac{x}{2}\right)=0\) b) \(x-\dfrac{1}{8}=\dfrac{5}{8}\)
c) \(-\dfrac{1}{2}-\left(\dfrac{3}{2}+x\right)=-2\) d) \(x+\dfrac{1}{3}=\dfrac{-12}{5}.\dfrac{10}{6}\)
a, \(\dfrac{5}{2}-3\left(\dfrac{1}{3}-x\right)=\dfrac{1}{4}-7x\)
b, \(\left(1+\dfrac{1}{2}+\dfrac{1}{3}+...+\dfrac{1}{2008}\right).x=\dfrac{2009}{1}+\dfrac{2010}{2}+...+\dfrac{5016}{2008}-2008\)
c, \(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{2}{x.\left(x+1\right)}=\frac{2001}{2003}\)
GIÚP VỚI , MIK CẦN GẤP
Tìm x:
d) \(\dfrac{-5}{6}-x=\dfrac{7}{12}+\dfrac{-1}{3}\)
e) \(\dfrac{x+3}{-15}=\dfrac{1}{3}\)
f) \(\left(4,5-2x\right).\left(-1\dfrac{4}{7}\right)=\dfrac{11}{14}\)
Tìm x:
a) \(\dfrac{5}{4}+\left(2x-\dfrac{1}{2}\right)=\dfrac{5}{6}\)
b) \(\dfrac{3}{2}-\left(x+\dfrac{1}{4}\right)=\dfrac{5}{8}\)
c) \(\dfrac{x}{3}=\dfrac{12}{x}\)
Giúp với!
Tìm x:
a, \(\left(12-12\dfrac{1}{3}\right):x+\dfrac{1}{6}=\dfrac{-2}{3}\)
b, \(\dfrac{4}{x}=\dfrac{x}{16}\)
\(\dfrac{7}{6}-\dfrac{1}{6}.\left(x-2\right)=\dfrac{7}{12}-1\dfrac{1}{3}\)
\(a,\left(\dfrac{37}{9}+\dfrac{13}{4}\right)x\dfrac{9}{4}+\dfrac{11}{4}\) b,\(1+\left(\dfrac{9}{10}-\dfrac{-4}{5}\right):\dfrac{19}{6}\)
c,\(\dfrac{1}{4}-\dfrac{3}{2}+\dfrac{1}{2}x\dfrac{12}{5}\)
Giúp mik nha:>
