\(\Leftrightarrow x\cdot\dfrac{1}{3}\cdot\left(\dfrac{3}{2\cdot5}+\dfrac{3}{5\cdot8}+...+\dfrac{3}{32\cdot35}\right)=\dfrac{33}{70}\)
=>\(x\cdot\dfrac{1}{3}\left(\dfrac{1}{2}-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{8}+...+\dfrac{1}{32}-\dfrac{1}{35}\right)=\dfrac{33}{70}\)
=>\(x\cdot\dfrac{1}{3}\cdot\dfrac{33}{70}=\dfrac{33}{70}\)
=>x=3
x/2x5+x/5x8+x/8x11+x/11x14+...+x/32x35=33/70
A=\(\dfrac{3}{5x8}\)+\(\dfrac{3}{8x11}\)+\(\dfrac{3}{11x14}\)+....+\(\dfrac{3}{100x103}\)
A=\(\dfrac{3}{5x8}\)+\(\dfrac{3}{8x11}\)+....+\(\dfrac{3}{2009x2012}\)
3 x (\(\dfrac{x}{4}\) + \(\dfrac{x}{28}\) + \(\dfrac{x}{70}\) + \(\dfrac{x}{130}\) ) =\(\dfrac{60}{13}\)
9 - 3 x ( X - 9 ) = 6
4 + 6 x ( X + 1 ) 70
\(\dfrac{X}{13}+\dfrac{15}{26}=\dfrac{46}{52}\)
\(\dfrac{11}{14}-\dfrac{3}{X}=\dfrac{5}{14}\)
5 x ( 3 + 7 x X ) = 40
X x 6 + 12 : 3 = 120
X x 3,7 + X x 6,3 = 120
( 15 x 24 - X ) : 0,25 = 100 : \(\dfrac{1}{4}\)
71 + 65 x 4 = \(\dfrac{X+140}{X}\)+ 260
( X +1 ) + ( X + 4 ) + ( x + 7 ) + ...... + (X + 28 ) = 155
đây là bài tìm X
Bài 6: Tìm x, biết
a) \(\dfrac{3}{2}\) x \(\dfrac{4}{5}\) - X =\(\dfrac{2}{3}\)
b) X x 3\(\dfrac{1}{3}\) = 3\(\dfrac{1}{3}\) : 4\(\dfrac{1}{4}\)
c) 5\(\dfrac{2}{3}\) : x = 3\(\dfrac{2}{3}\) - 2\(\dfrac{1}{2}\)
Tìm x biết: x - 1 = \(\dfrac{6}{7}\) + \(\dfrac{1}{7}\) x\(\dfrac{2}{7}\) + \(\dfrac{1}{7}\) x \(\dfrac{5}{7}\)
Tìm x biết:
\(\dfrac{x}{x+1}=\dfrac{1}{1x2}+\dfrac{1}{2x3}+\dfrac{1}{3x4}+...+\dfrac{1}{31x32}\)
Trả lời nhanh giúp mìn nhé
Tìm x:
\(\dfrac{3}{5}\) : x = \(\dfrac{1}{3}+\dfrac{1}{2}\) x : \(\dfrac{7}{12}\) = 2 x - \(\dfrac{3}{2}\) = \(\dfrac{11}{4}-\dfrac{5}{4}\) x + \(\dfrac{5}{4}\) = \(\dfrac{3}{2}+\dfrac{7}{12}\)
