\(\frac{3}{1.4}+\frac{3}{4.7}+..+\frac{3}{97.100}=\frac{0,33x}{2009}\)
\(1-\frac{1}{4}+\frac{1}{4}-...-\frac{1}{100}=\frac{0,33x}{2009}\)
\(1-\frac{1}{100}=\frac{0,33x}{2009}\)
\(\frac{99}{100}=\frac{0,33x}{20009}\Rightarrow2009.99=100.0,33x\)
x=6027
\(\frac{1}{4}+\frac{1}{28}+\frac{1}{70}+...+\frac{1}{9700}=\frac{0,33x}{2009}\)
Mọi ngừi giúp Natasha với.
\(\frac{1}{4}+\frac{1}{28}+...+\frac{1}{9700}=\frac{0,33x}{2009}\)
Ai xong đầu tiên thì Tasha sẽ tick cho nha.
Iu mn nhìu.
1/4+1/28+/1/70+...+1/9700=0,33x/2009
Tính nhanh:
\(\frac{1}{4}+\frac{1}{28}+\frac{1}{70}+...+\frac{1}{9700}\)
Tính nhanh tổng số
\(\frac{1}{4}\)+ \(\frac{1}{28}\)+ \(\frac{1}{70}\)+ \(\frac{1}{130}\)+ ... + \(\frac{1}{9700}\)
\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}+...+\frac{2}{x\left(x-1\right)}=\frac{2007}{2009}\). Tim x
Tim x thuoc Z, biet: \(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{1}{x\left(x+1\right):2}=\frac{2009}{2011}\)
Tính tổng :
M = \(\frac{1}{4}+\frac{1}{28}+\frac{1}{70}+\frac{1}{120}+\).............(Biết rằng M có 30 số hạng )
Tìm x biết
a, ( x + 1 ) + ( x + 4 ) + ( x + 7 ) + .... + ( x + 28 ) = 155
b, 1 + \(\frac{1}{3}\) + \(\frac{1}{6}\)+ \(\frac{1}{10}\) + ..... + \(\frac{2}{x.\left(x+1\right)}\)= \(1\frac{2009}{2010}\)
c, \(\left(\frac{2}{11.13}+\frac{2}{13.15}+\frac{2}{15.17}+....+\frac{2}{19.21}\right)\) . 462 - x = 19
