\(\dfrac{x}{2008}+\dfrac{x}{2009}-\dfrac{x}{2007}=1+\dfrac{1}{2008}-\dfrac{1}{2009}-\dfrac{2}{2007}\)
\(\Rightarrow x = \dfrac{2007.2008.2009+2009.2007-2008.2007-2.2008.2009}{2009.2007+2008.2007-2008.2009}\)
tìm x biết \(\frac{1}{1x2}+\frac{1}{2x3}+....+\frac{1}{x\left(x+1 \right)}=\frac{2008}{2009}\)
A=\(\frac{\frac{2008}{2}+\frac{2007}{3}+\frac{2006}{4}+...+\frac{2008}{2009}}{\frac{2008}{1}+\frac{2007}{2}+\frac{2006}{3}+...+\frac{1}{2008}}\)
1 / giải phương trình sau:
\(\frac{1}{\left(x+2000\right).\left(x+2001\right)}+\frac{1}{\left(x+2001\right).\left(x+2002\right)}...\frac{1}{\left(x+2006\right)\left(x+2007\right)}=\frac{7}{8}\)
Tìm x thuộc N biết:
\(\frac{1}{2}+\frac{1}{28}+\frac{1}{36}+...+\frac{2}{x.\left(x+1\right)}=\frac{3}{10}\)
\(A=\frac{2008+2007+2002+2001+...+3+2+1}{2008-2007+2006-2005 +...+3-2+1}\)
Tìm số nguyên x biết:
\(\left(\frac{1}{1\cdot101}+\frac{1}{2\cdot102}+...+\frac{1}{10\cdot110}\right)\cdot x=\frac{1}{1\cdot11}+\frac{1}{2\cdot12}+...+\frac{1}{100\cdot110}\)
Tìm x:
\(x.\frac{1}{2}-x.\frac{2}{3}+x.\frac{3}{4}-x.\frac{5}{6}=\frac{5}{6}-\frac{3}{4}+\frac{2}{3}-\frac{1}{2}\)
help me pleas
Help tìm x: \(\left|x+\frac{1}{2}\right|+\left|x+\frac{1}{6}\right|+\left|x+\frac{1}{12}\right|+\left|x+\frac{1}{20}\right|+...+\left|x+\frac{1}{110}\right|=11x\)
