Các câu hỏi tương tự
Tìm \(x\):
\(\left(\frac{1}{1\times2}+\frac{1}{2\times3}+\frac{1}{3\times4}+.....\frac{1}{2009\times2010}\right)\times x=2009\)
Tìm x biết \(\left(\frac{1}{1\times2}+\frac{1}{2\times3}+\frac{1}{3\times4}+\frac{1}{4\times5}+\frac{1}{5\times6}\right)\times10-x=0\)
Tìm x biết :
\(\frac{10}{1\times2}+\frac{10}{2\times3}+...+\frac{10}{x\times\left(x+1\right)}=9\)
Tính nhanh : \(\frac{1}{8}\div12,5\%+\left(\frac{1\times2\times3+6\times4\times2}{5\times3\times1+5\times15\times25}+\frac{1}{2}\div50\%\right)-\left(\frac{1}{16}\div6,25\%+\frac{3+2+1+2+4+6}{1+3+5+25+15+5}\right)-\frac{1}{4}\div25\%\)
\(\frac{1}{1\times2}+\frac{1}{2\times3}+\frac{1}{3\times4}+......+\frac{1}{2010\times2011}\)
Tìm X biết : {44 + 2010/1x2 + 2006/2x3 + 2000/3x4 +........+ 32/44x45} = 44/45
Tính nhanh :
A = \(\frac{1,25\times10\div0,25\times24,4\times2}{6,1\times2\times6,25\times4\div0,5}+\left(1-\frac{1}{2}\right)\times\left(1-\frac{1}{3}\right)\times\left(1-\frac{1}{4}\right).........\left(1-\frac{1}{19}\right)\times\left(1-\frac{1}{20}\right)\)
tính giá trị biểu thức: \(\frac{1\times2\times3}{1\times6\times8}\times\frac{6\times4\times5}{3\times2\times2\times10}\)
Tìm số tự nhiên biết : \(\frac{1}{2\times3}+\frac{1}{3\times4}+\frac{1}{4\times5}+...+\frac{1}{a\times\left(a+1\right)}=\frac{49}{100}\)
Trả lời : a =................