\(\frac{1}{15}x1\frac{1}{16}x1\frac{1}{17}x...x1\frac{1}{2009}x1\frac{1}{2010}=\frac{1}{15}x\frac{17}{16}x\frac{18}{17}x...x\frac{2010}{2009}x\frac{2011}{2010}=\frac{2011}{240}\)
Tính nhanh \(1\frac{1}{15}\times1\frac{1}{16}\times1\frac{1}{17}\times...\times1\frac{1}{2009}\times1\frac{1}{2010}\)
1 x \(\frac{1}{15}\) x 1\(\frac{1}{16}\) x 1\(\frac{1}{17}\) x............x 1\(\frac{1}{2016}\) x 1\(\frac{1}{2017}\)
\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+...+\frac{2}{x\left(x-1\right)}=\frac{2007}{2009}\)
Tìm x :
a) (131,4-80,8) nhân x :2,3+21,84 nhân 2= 65,68
b) ( \(\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+...+\frac{1}{2010}\) ) nhân x=2009
\(1\frac{1}{15}\)x \(1\frac{1}{16}\)x \(1\frac{1}{17}\)x .......... x \(1\frac{1}{2016}\)x \(1\frac{1}{2017}\)
\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+...+\frac{2}{x\left(x-1\right)}=\frac{2007}{2009}\)
\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+.....+\frac{2}{x\left(x-1\right)}=\frac{2007}{2009}\)
Tính nhanh:
1 x \(\frac{1}{15}\)x 1\(\frac{1}{16}\)x \(1\frac{1}{17}\)x........x \(1\frac{1}{2016}\)x \(1\frac{1}{2017}\)
Tính nhanh giúp mình nha!
x-\(\left(\frac{20}{11.13}+\frac{20}{13.15}+\frac{20}{15.17}+...+\frac{20}{53.55}\right)=\frac{3}{11}\)
\(\frac{7}{4}x.\left(\frac{33}{12}+\frac{3333}{2020}+\frac{333333}{303030}+\frac{33333333}{42424242}\right)=22\)
\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+...+\frac{2}{x\left(x-1\right)}=\frac{2007}{2009}\)
\(\left(\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}+\frac{1}{64}+\frac{1}{128}+\frac{1}{256}\right).x=1\)
