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19 tháng 1 2018

\(\dfrac{x-3}{2013}+\dfrac{x-2}{2014}=\dfrac{x-2014}{2}+\dfrac{x-2013}{3}\)

\(\Leftrightarrow\left(\dfrac{x-3}{2013}-1\right)+\left(\dfrac{x-2}{2014}-1\right)=\left(\dfrac{x-2014}{2}-1\right)+\left(\dfrac{x-2013}{3}-1\right)\)\(\Leftrightarrow\dfrac{x-2016}{2013}+\dfrac{x-2016}{2014}=\dfrac{x-2016}{2}+\dfrac{x-2016}{3}\)

\(\Leftrightarrow\left(x-2016\right)\left(\dfrac{1}{2013}+\dfrac{1}{2014}-\dfrac{1}{2}-\dfrac{1}{3}\right)=0\)

Hiển nhiên \(\dfrac{1}{2013}+\dfrac{1}{2014}-\dfrac{1}{2}-\dfrac{1}{3}< 0.\)

Vậy \(S=\left\{2016\right\}\)

19 tháng 1 2018

\(\dfrac{x-3}{2013}-1+\dfrac{x-2}{2014}-1=\dfrac{x-2014}{2}-1+\dfrac{x-2013}{3}-1\)

=> \(\dfrac{x-3-2013}{2013}+\dfrac{x-2-2014}{2014}=\dfrac{x-2014-2}{2}+\dfrac{x-2013-3}{3}\)

=> \(\dfrac{x-2016}{2013}+\dfrac{x-2016}{2014}-\dfrac{x-2016}{2}-\dfrac{x-2016}{3}=0\)

=> (x-2016)\(\left(\dfrac{1}{2013}+\dfrac{1}{2014}-\dfrac{1}{2}-\dfrac{1}{3}\right)=0\)

=> x-2016=0

=> x=2016

a: \(\Leftrightarrow x+2016=0\)

hay x=-2016

b: \(\Leftrightarrow x-100=0\)

hay x=100

\(\Leftrightarrow\dfrac{5-x^2}{2012}=\dfrac{4-x^2}{2013}+1-\dfrac{x^2-3}{2014}\)

\(\Leftrightarrow\dfrac{5-x^2}{2012}+1=\dfrac{4-x^2}{2013}+1+\dfrac{3-x^2}{2014}+1\)

\(\Leftrightarrow2017-x^2=0\)

hay \(x\in\left\{\sqrt{2017};-\sqrt{2017}\right\}\)

11 tháng 5 2023

\(\dfrac{x}{2012}+\dfrac{x+1}{2013}+\dfrac{x+2}{2014}+\dfrac{x+3}{2015}+\dfrac{x+4}{2016}=5\)

\(\Leftrightarrow\dfrac{x}{2012}+\dfrac{x+1}{2013}+\dfrac{x+2}{2014}+\dfrac{x+3}{2015}+\dfrac{x+4}{2016}-5=0\)

\(\Leftrightarrow\dfrac{x}{2012}-1+\dfrac{x+1}{2013}-1+\dfrac{x+2}{2014}-1+\dfrac{x+3}{2015}+\dfrac{x+4}{2016}-1=0\)

\(\Leftrightarrow\dfrac{x-2012}{2012}+\dfrac{x-2012}{2013}+\dfrac{x-2012}{2014}+\dfrac{x-2012}{2015}+\dfrac{x-2012}{2016}=0\)

\(\Leftrightarrow\left(x-12\right).\left(\dfrac{1}{2012}+\dfrac{1}{2013}+\dfrac{1}{2014}+\dfrac{1}{2015}+\dfrac{1}{2016}\right)=0\)

\(\Leftrightarrow x-12=0\)

\(\Leftrightarrow x=12\)

1 tháng 3 2017

\(\Leftrightarrow\dfrac{x+1}{2015}+1+\dfrac{x+2}{2014}+1=\dfrac{x}{1008}+\dfrac{x+3}{2013}+1\)

\(\Leftrightarrow\dfrac{x+2016}{2015}+\dfrac{x+2016}{2014}=\dfrac{x}{1008}+\dfrac{x+2016}{2013}\)

\(\Leftrightarrow\dfrac{x+2016}{2015}+\dfrac{x+2016}{2014}-\dfrac{x}{1008}-\dfrac{x+2016}{2013}=0\)

\(\Leftrightarrow\left(x+2016\right)\left(-\dfrac{x}{1008}+\dfrac{1}{2015}+\dfrac{1}{2014}+\dfrac{1}{2013}\right)=0\)

\(\Leftrightarrow x+2016=0\)

\(\Leftrightarrow x=-2016\)

1 tháng 3 2017

\(\frac{x+1}{2015}+\frac{x+2}{2014}=\frac{x}{1008}+1+\frac{x+3}{2013}\)

\(\Leftrightarrow\frac{x+1}{2015}+1+\frac{x+2}{2014}+1=\frac{x+1008}{1008}+1+\frac{x+3}{2013}+1\)

\(\Leftrightarrow\frac{x+2016}{2015}+\frac{x+2016}{2014}=\frac{x+2016}{1008}+\frac{x+2016}{2013}\)

\(\Leftrightarrow\left(x+2016\right)\left(\frac{1}{2015}+\frac{1}{2014}-\frac{1}{1008}-\frac{1}{2013}\right)=0\)

\(\left(\frac{1}{2015}+\frac{1}{2014}-\frac{1}{1008}+\frac{1}{2013}\right)\ne0\)nên

x+2016=0\(\Leftrightarrow\)x=-2016

NV
21 tháng 2 2019

a/ Đặt \(x^2+x+1=a\Rightarrow x^2+x+2=a+1\)

Pt trở thành \(a\left(a+1\right)-12=0\Leftrightarrow a^2+a-12=0\)

\(\Leftrightarrow a^2-3a+4a-12=0\Leftrightarrow a\left(a-3\right)+4\left(a-3\right)=0\)

\(\Leftrightarrow\left(a-3\right)\left(a+4\right)=0\Leftrightarrow\left[{}\begin{matrix}a=3\\a=-4\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x^2+x+1=3\\x^2+x+1=-4\end{matrix}\right.\) \(\Leftrightarrow\left[{}\begin{matrix}x^2+x-2=0\\x^2+x+5=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}\left(x-1\right)\left(x+2\right)=0\\\left(x+\dfrac{1}{2}\right)^2+\dfrac{19}{4}=0\left(vn\right)\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x=1\\x=-2\end{matrix}\right.\)

2/ \(\dfrac{x+1}{2014}+1+\dfrac{x+2}{2013}+1=\dfrac{x+3}{2012}+1+\dfrac{x+4}{2011}+1\)

\(\Leftrightarrow\dfrac{x+2015}{2014}+\dfrac{x+2015}{2013}=\dfrac{x+2015}{2012}+\dfrac{x+2015}{2011}\)

\(\Leftrightarrow\left(x+2015\right)\left(\dfrac{1}{2014}+\dfrac{1}{2013}-\dfrac{1}{2012}-\dfrac{1}{2011}\right)=0\)

\(\Leftrightarrow x+2015=0\) (do \(\dfrac{1}{2014}+\dfrac{1}{2013}-\dfrac{1}{2012}-\dfrac{1}{2011}\ne0\))

\(\Rightarrow x=-2015\)

18 tháng 4 2018

Ta có : \(\dfrac{x+1}{2014}+\dfrac{x+2}{2013}+\dfrac{x+3}{2012}+\dfrac{x+4}{2011}=0\)

\(\Leftrightarrow\left(\dfrac{x+1}{2014}+1\right)+\left(\dfrac{x+2}{2013}+1\right)+\left(\dfrac{x+3}{2012}+1\right)+\left(\dfrac{x+4}{2011}+1\right)=4\)

\(\Leftrightarrow\dfrac{x+2015}{2014}+\dfrac{x+2015}{2013}+\dfrac{x+2015}{2012}+\dfrac{x+2015}{2011}=4\Leftrightarrow\left(x+2015\right)\left(\dfrac{1}{2014}+\dfrac{1}{2013}+\dfrac{1}{2012}+\dfrac{1}{2011}\right)=4\) \(\Leftrightarrow\left(x+2015\right).0,002=4\) ( mik lấy gần bằng nha )

\(\Leftrightarrow x+2015=2000\Leftrightarrow x=-15\)

Vậy phương trình có nghiệm là x=-15

13 tháng 12 2018

\(\Rightarrow\frac{x}{2010}+\frac{x+1}{2011}+\frac{x+2}{2012}+\frac{x+3}{2013}+\frac{x+4}{2014}-5=0\)

\(\left(\frac{x}{2010}-1\right)+\left(\frac{x+1}{2011}-1\right)+\left(\frac{x+2}{2012}-1\right)\)\(+\left(\frac{x+3}{2013}-1\right)+\left(\frac{x+4}{2014}-1\right)=0\)

\(\frac{x-2010}{2010}+\frac{x-2010}{2011}+\frac{x-2010}{2012}+\frac{x-2010}{2013}+\frac{x-2010}{2014}=0\)

\(\left(x-2010\right).\left(\frac{1}{2010}+\frac{1}{2011}+\frac{1}{2012}+\frac{1}{2013}+\frac{1}{2014}\right)=0\)

mà \(\frac{1}{2010}+\frac{1}{2011}+\frac{1}{2012}+\frac{1}{2013}+\frac{1}{2014}\ne0\Rightarrow x+2010=0\Rightarrow x=-2010\)

Vậy x=-2010

30 tháng 11 2017

\(\dfrac{x+1}{2015}+\dfrac{x+2}{2014}+\dfrac{x+3}{2013}+\dfrac{x+4}{2012}+\dfrac{x+2024}{2}=0\)

\(\Leftrightarrow(\dfrac{x+1}{2015}+1)+(\dfrac{x+2}{2014}+1)+(\dfrac{x+3}{2013}+1)+(\dfrac{x+4}{2012}+1)+\dfrac{x+2024}{2}-4=0\)\(\Leftrightarrow\dfrac{x+2016}{2015}+\dfrac{x+2016}{2014}+\dfrac{x+2016}{2013}+\dfrac{x+2016}{2012}+\dfrac{x+2016}{2}=0\)\(\Leftrightarrow\left(x+2016\right)\left(\dfrac{1}{2015}+\dfrac{1}{2014}+\dfrac{1}{2013}+\dfrac{1}{2012}+\dfrac{1}{2}\right)=0\)

Hiển nhiên: \(\dfrac{1}{2015}+\dfrac{1}{2014}+\dfrac{1}{2013}+\dfrac{1}{2012}+\dfrac{1}{2}>0\)

\(\Leftrightarrow x+2016=0\Leftrightarrow x=-2016\)

14 tháng 12 2018

\(\dfrac{x}{2010}+\dfrac{x+1}{2011}+\dfrac{x+2}{2012}+\dfrac{x+3}{2013}+\dfrac{x+4}{2014}=5\)

\(\Leftrightarrow\left(\dfrac{x}{2010}-1\right)+\left(\dfrac{x+1}{2011}-1\right)+\left(\dfrac{x+2}{2012}-1\right)+\left(\dfrac{x+3}{2013}-1\right)+\left(\dfrac{x+4}{2014}-1\right)=0\)

\(\Leftrightarrow\dfrac{x-2010}{2010}+\dfrac{x-2010}{2011}+\dfrac{x-2010}{2012}+\dfrac{x-2010}{2013}+\dfrac{x-2010}{2014}=0\)

\(\Leftrightarrow\left(x-2010\right)\left(\dfrac{1}{2010}+\dfrac{1}{2011}+\dfrac{1}{2012}+\dfrac{1}{2013}+\dfrac{1}{2014}\right)=0\)

\(\Leftrightarrow x=2010\)