Lời giải:
$\frac{x+3}{2007}-\frac{x+3}{2008}=\frac{x+3}{2009}-\frac{x+3}{2010}$
$(x+3)(\frac{1}{2007}-\frac{1}{2008})=(x+3)(\frac{1}{2009}-\frac{1}{2010})$
$(x+3).\frac{1}{2007.2008}=(x+3).\frac{1}{2009.2010}$
$(x+3)(\frac{1}{2007.2008}-\frac{1}{2009.2010})=0$
$\Rightarrow x+3=0$ (do $\frac{1}{2007.2008}-\frac{1}{2009.2010}\neq 0$)
$\Rightarrow x=-3$
a, \(\dfrac{5}{2}-3\left(\dfrac{1}{3}-x\right)=\dfrac{1}{4}-7x\)
b, \(\left(1+\dfrac{1}{2}+\dfrac{1}{3}+...+\dfrac{1}{2008}\right).x=\dfrac{2009}{1}+\dfrac{2010}{2}+...+\dfrac{5016}{2008}-2008\)
c, \(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{2}{x.\left(x+1\right)}=\frac{2001}{2003}\)
GIÚP VỚI , MIK CẦN GẤP
Tìm x, y biết \(|x-2007|+|x-2008|-|x-2009|+|x-2010|=3\)
Bài 2 : So sánh
\(A=\dfrac{2008}{2009}+\dfrac{2009}{2010}+\dfrac{2010}{2011}vàB=\dfrac{2008+2009+2010}{2009+2010+2011}\)
Tìm x biết:
\(a,\dfrac{4}{5}+x=\dfrac{2}{3}\)
\(b,\dfrac{-5}{6}-x=\dfrac{2}{3}\)
\(c,\dfrac{1}{2}x+\dfrac{3}{4}=\dfrac{-3}{10}\)
\(d,\dfrac{x}{3}-\dfrac{1}{2}=\dfrac{1}{5}\)
\(e,\dfrac{x+3}{15}=\dfrac{1}{3}\)
\(h,x+30\%x=-1,3\)
\(k,3\dfrac{1}{3}x+16\dfrac{1}{4}=13,25\)
\(m,\dfrac{x-6}{2}=\dfrac{50}{x-6}\)
\(n,x-13,4=24,5-6,7.5,2\)
\(p,15,7x+3,6x=-96,5\)
\(q,2,5x-11,6=-59,1\)
Tìm x biết: a) \(\dfrac{6}{-x}=\dfrac{x}{-24}\) b) \(x-\dfrac{7}{12}x+\dfrac{3}{8}x=\dfrac{5}{24}\)
c)\(\left(x-\dfrac{1}{3}\right)^2-\dfrac{1}{2}=1\dfrac{3}{4}\) d) \(\dfrac{x-3}{-2}=\dfrac{-8}{x-3}\)
e) \(\dfrac{9}{x}=\dfrac{-35}{105}\) f) \(\left(x-\dfrac{1}{2}\right)\left(-3-\dfrac{x}{2}\right)=0\)
tìm x biết
a , \(\dfrac{-3}{10}\)-(\(\dfrac{-1}{5}\) +x)=\(\dfrac{-3}{2}\)
b, -(-x+ \(\dfrac{3}{4}\))- \(\dfrac{12}{8}\).- \(\dfrac{32}{15}\)=- \(\dfrac{-1}{2}\)
c, \(\dfrac{x-3}{x+5}\)=\(\dfrac{4}{3}\)
Tìm x:
a) \(\dfrac{-3}{7}\).x=\(\dfrac{3}{56}\).\(\dfrac{28}{9}\)
b) x-\(\dfrac{3}{16}\)=\(\dfrac{7}{15}\):\(\dfrac{3}{5}\)
c) \(\dfrac{2}{5}\)+\(\dfrac{1}{5}\).x=\(\dfrac{5}{6}\)
d) \(\dfrac{3}{4}\)x-\(\dfrac{2}{5}\)x=\(\dfrac{3}{7}\).\(\dfrac{1}{6}\)+\(\dfrac{5}{7}\).\(\dfrac{1}{6}\)
*Lưu ý: Trình bày chi tiết kết quả.
Tìm x, biết:
a) \(\dfrac{2}{5}\) + \(\dfrac{3}{4}\): x = \(\dfrac{-1}{2}\)
b) \(\dfrac{5}{7}\) - \(\dfrac{2}{3}\) . x = \(\dfrac{4}{5}\)
c) \(\dfrac{1}{2}\) x + \(\dfrac{2}{3}\) x = \(\dfrac{-2}{3}\)
d) \(\dfrac{4}{7}\)x - x= \(\dfrac{-9}{14}\)
tìm x e Q
a) \(\dfrac{x+1}{3}+\dfrac{x+1}{4}+\dfrac{x+1}{5}=\dfrac{x+1}{6}\)
b) \(\dfrac{x+1}{2020}+\dfrac{x+2}{2019}=\dfrac{x+3}{2018}+\dfrac{x+4}{2017}\)
c) \(\dfrac{x+2}{327}+\dfrac{x+3}{326}+\dfrac{x+4}{325}+\dfrac{x+5}{324}+\dfrac{x+349}{5}=0\)
\(\dfrac{x-3}{13}+\dfrac{x-3}{14}=\dfrac{x-3}{15}+\dfrac{x-3}{16}\)
Tìm x
