giải pt
\(\frac{2-x}{2014}\)-1=\(\frac{1-x}{2015}\)-\(\frac{x}{2016}\)
Giải pt:
\(\frac{\sqrt{x-2014}-1}{x-2014}+\frac{\sqrt{y-2015}-1}{y-2015}+\frac{\sqrt{z-2016}-1}{z-2016}=\frac{3}{4}\)
Đặt \(\sqrt{x-2014}=a;\sqrt{y-2015}=b;\sqrt{z=2016}=c\)(với a,b,c>0). Khi đó pt trở thành:
\(\frac{a-1}{a^2}+\frac{b-1}{b^2}+\frac{c-1}{c^2}=\frac{3}{4}\)\(\Leftrightarrow\left(\frac{1}{4}-\frac{1}{a}+\frac{1}{a^2}\right)+\left(\frac{1}{4}-\frac{1}{b}+\frac{1}{b^2}\right)+\left(\frac{1}{4}-\frac{1}{c}+\frac{1}{c^2}\right)=0\)
\(\Leftrightarrow\left(\frac{1}{2}-\frac{1}{a}\right)^2+\left(\frac{1}{2}-\frac{1}{b}\right)^2+\left(\frac{1}{2}-\frac{1}{c}\right)^2=0\Leftrightarrow a=b=c=2\)
\(\Rightarrow x=2018;y=2019;z=2020\)
\(\frac{\sqrt{x-2014}-1}{x-2014}+\frac{\sqrt{y-2015}-1}{y-2015}+\frac{\sqrt{z-2016}-1}{z-2016}=\frac{3}{4}\)
\(\frac{\sqrt{x-2014}}{x-2014}+\frac{\sqrt{y-2015}}{y-2015}+\frac{\sqrt{z-2016}}{z-2016}-\left(\frac{1}{x-2014+y-2015+z-2016}\right)=\frac{3}{4}\)
\(\frac{\sqrt{x-2014}}{x-2014}+\frac{\sqrt{y-2015}}{y-2015}+\frac{\sqrt{z-2016}}{z-2016}+0=\frac{3}{4}\)
\(\frac{\sqrt{x}-\sqrt{2014}}{x-2014}+\frac{\sqrt{y}-\sqrt{2015}}{y-2015}+\frac{\sqrt{z}-\sqrt{2016}}{z-2016}=\frac{3}{4}\)
\(x=2018,y=2019,z=2020\)
ĐK : \(\hept{\begin{cases}x>2014\\y>2015\\z>2016\end{cases}}\)
\(\frac{\sqrt{x-2014}-1}{x-2014}+\frac{\sqrt{y-2015}-1}{y-2015}+\frac{\sqrt{z-2016}-1}{z-2016}=\frac{3}{4}\)
\(\Leftrightarrow\frac{1}{4}-\frac{\sqrt{x-2014}-1}{x-2014}+\frac{1}{4}-\frac{\sqrt{y-2015}-1}{y-2015}+\frac{1}{4}-\frac{\sqrt{z-2016}-1}{z-2016}=0\)
\(\Leftrightarrow\frac{x-2010-4\sqrt{x-2014}}{4\left(x-2014\right)}+\frac{y-2011-4\sqrt{y-2015}}{4\left(y-2015\right)}+\frac{z-2012-4\sqrt{z-2016}}{4\left(x-2014\right)}=0\)
\(\Leftrightarrow\frac{\left(2-\sqrt{x-2014}\right)^2}{4\left(x-2014\right)}+\frac{\left(2-\sqrt{y-2015}\right)^2}{4\left(y-2015\right)}+\frac{\left(2-\sqrt{z-2016}\right)^2}{4\left(z-2016\right)}=0\)( 1 )
Mà \(\hept{\begin{cases}\frac{\left(2-\sqrt{x-2014}\right)^2}{4\left(x-2014\right)}\ge0\forall x>2014\\\frac{\left(2-\sqrt{y-2015}\right)^2}{4\left(y-2015\right)}\ge0\forall y>2015\\\frac{\left(2-\sqrt{z-2016}\right)^2}{4\left(z-2016\right)}\ge0\forall z>2016\end{cases}}\)( 2 )
Từ ( 1 ) và ( 2 ) => \(\hept{\begin{cases}\left(2-\sqrt{x-2014}\right)^2=0\\\left(2-\sqrt{y-2015}\right)^2=0\\\left(2-\sqrt{z-2016}\right)^2=0\end{cases}}\)
<=> \(\hept{\begin{cases}\sqrt{x-2014}=2\\\sqrt{y-2015}=2\\\sqrt{z-2016}=2\end{cases}}\)<=>\(\hept{\begin{cases}x=2018\\y=2019\\z=2020\end{cases}}\)( tmđk )
Vậy ( x ; y ; z ) = ( 2018 ; 2019 ; 2020 )
\(\frac{x+2}{2014}+\frac{x+1}{2015}=\frac{x}{2016}+\frac{x-1}{2017}\)
Tìm x của pt bằng cach giải ko cần qui đồng.
Bạn nào trả lời đúng mình tick cho. Thanks nhiều! (^ - ^)
(x+2/2014)+1 + (x+1/2015)+1 = (x+2016)+1 + (x-1/2017)+1
(x+2016/2014) + (x+2016/2015) - (x+2016/2016) - (x-2016/2017)=0
=>(x+2016)(1/2014+1/2015-1/2016-1/2017)
vì 1/2014+1/2015-1/2016-1/2017 luôn khác 0 => x+2016=0
=> x=-2016
Nghiệm nhỏ nhất của pt\(\frac{1}{2\sqrt{x}-2014}+\frac{1}{3\sqrt{x}+2013}=\frac{1}{2015-4\sqrt{x}}+\frac{1}{9\sqrt{x}-2016}\)
Giải pt: \(\frac{x-3}{2014}+\frac{x-2}{2015}=\frac{x-1}{1008}+\frac{x}{2017}-1\)
Giải phương trình: \(\frac{x}{2017}+\frac{x+1}{2016}=\frac{x+2}{2015}+\frac{x+3}{2014}\)
PT đã cho tương đương với:
\(\left(\frac{x}{2017}+1\right)+\left(\frac{x+1}{2016}+1\right)=\left(\frac{x+2}{2015}+1\right)+\left(\frac{x+3}{2014}+1\right)\)
\(\Leftrightarrow\frac{x+2017}{2017}+\frac{x+2017}{2016}=\frac{x+2017}{2015}+\frac{x+2017}{2014}\)
\(\Leftrightarrow\left(x+2017\right)\left(\frac{1}{2017}+\frac{1}{2016}\right)=\left(x+2017\right)\left(\frac{1}{2015}+\frac{1}{2014}\right)\)
\(\Leftrightarrow x+2017=0\Leftrightarrow x=-2017\)
Ta có: \(\frac{x}{2017}+\frac{x+1}{2016}=\frac{x+2}{2015}+\frac{x+3}{2014}\)
\(\Leftrightarrow\frac{x}{2017}+1+\frac{x+1}{2016}+1=\frac{x+2}{2015}+1+\frac{x+3}{2014}+1\)
\(\Leftrightarrow\frac{x+2017}{2017}+\frac{x+2017}{2016}=\frac{x+2017}{2015}+\frac{x+2017}{2014}\)
\(\Leftrightarrow\frac{x+2017}{2017}+\frac{x+2017}{2016}-\frac{x+2017}{2015}-\frac{x+2017}{2014}=0\)
\(\Leftrightarrow\left(x+2017\right)\left(\frac{1}{2017}+\frac{1}{2016}-\frac{1}{2015}-\frac{1}{2014}\right)=0\)
mà \(\frac{1}{2017}+\frac{1}{2016}-\frac{1}{2015}-\frac{1}{2014}\ne0\)
nên x+2017=0
hay x=-2017
Vậy: S={-2017}
giải pt
\(\frac{x-3}{2015}+\frac{x-2}{2016}=\frac{x-2016}{2}+\frac{x-2015}{3}\)
\(\frac{x-3}{2015}+\frac{x-2}{2016}=\frac{x-2016}{2}+\frac{x-2015}{3}\)
\(\Leftrightarrow\left(\frac{x-3}{2015}-1\right)+\left(\frac{x-2}{2016}-1\right)=\left(\frac{x-2016}{2}-1\right)+\left(\frac{x-2015}{3}-1\right)\)
\(\frac{x-2018}{2015}+\frac{x-2018}{2016}-\frac{x-2018}{2}-\frac{x-2018}{3}=0\)
\(\Leftrightarrow\left(x-2018\right).\left(\frac{1}{2015}+\frac{1}{2016}-\frac{1}{2}-\frac{1}{3}\right)=0\)
Vì \(\frac{1}{2015}+\frac{1}{2016}-\frac{1}{2}-\frac{1}{3}< 0\)
nên x - 2018 = 0
,<=> x = 2018
Vậy phương có 1 nghiệm là x = 2018
pt <=> (x-3/2015 - 1) + (x-2/2016 - 1) = (x-2016/2 - 1) + (x-2015/3 - 1)
<=> x-2018/2015 + x-2018/2016 = x-2018/2 + x-2018/3
<=> x-2018/2 + x-2018/3 - x-2018/2015 - x-2018/2016 = 0
<=> (x-2018).(1/2+1/3-1/2015-1/2016) = 0
<=> x-2018 = 0 ( vì 1/2+1/3-1/2015-1/2016 > 0 )
<=> x=2018
Tk mk nha
Tìm x : \(\frac{x-1}{2016}+\frac{x-2}{2015}+\frac{x-3}{2014}+...+\frac{x-2016}{1}=2016\)
\(\frac{x-1}{2016}+\frac{x-2}{2015}+\frac{x-3}{2014}+...+\frac{x-2016}{1}=2016\)
\(\Rightarrow\frac{x-1}{2016}-1+\frac{x-2}{2015}-1+\frac{x-3}{2014}-1+...+\frac{x-2016}{1}-1=2016-2016\)
\(\Rightarrow\frac{x-2017}{2016}+\frac{x-2017}{2015}+\frac{x-2017}{2014}+...+\frac{x-2017}{1}=0\)
\(\Rightarrow\left(x-2017\right).\left(\frac{1}{2016}+\frac{1}{2015}+\frac{1}{2014}+...+1\right)=0\)
Mà \(\frac{1}{2016}+\frac{1}{2015}+\frac{1}{2014}+...+1\ne0\Rightarrow x-2017=0\)
=> x = 2017
Giải pt:
\(\frac{x-1}{2015}+\frac{x-2}{2014}+...+\frac{x-2014}{2}+x=4030\)
\(\frac{x-1}{2015}+\frac{x-2}{2014}+...+\frac{x-2014}{2}+x=4030\)
\(\Leftrightarrow\left(\frac{x-1}{2015}-1\right)+\left(\frac{x-2}{2014}-1\right)+...+\left(\frac{x-2014}{2}-1\right)+x-2016=0\)
\(\Leftrightarrow\frac{x-2016}{2015}+\frac{x-2016}{2014}+...+\frac{x-2016}{2}+x-2016=0\)
\(\Leftrightarrow\left(x-2016\right)\left(\frac{1}{2015}+\frac{1}{2014}+...+\frac{1}{2}+1\right)=0\)
\(\Leftrightarrow x=2016\)
a Alibaba
đến bước này a phải nói
1/2015+ 1/2014 +.....+1/2+1 khác 0
=> x-2016=0=>x=2016 chứ
hơi lm tắt anh oi có ng` sẽ ko hiểu =))
\(\frac{x-3}{2014}+\frac{x-2}{2015}=\frac{x-1}{1008}+\frac{x}{2017}-1\)
Hãy giải pt này
\(PT\Leftrightarrow\left(\frac{x-3}{2014}-1\right)+\left(\frac{x-2}{2015}-1\right)=\left(\frac{x-1}{1008}-2\right)+\left(\frac{x}{2017}-1\right)\)
\(\Leftrightarrow\frac{x-2017}{2014}+\frac{x-2017}{2015}=\frac{x-2017}{1008}+\frac{x-2017}{2017}\)
\(\Leftrightarrow\frac{x-2017}{2014}+\frac{x-2017}{2015}-\frac{x-2017}{1008}-\frac{x-2017}{2017}=0\)
\(\Leftrightarrow\left(x-2017\right)\left(\frac{1}{2014}+\frac{1}{2015}-\frac{1}{1008}-\frac{1}{2017}\right)=0\)
\(\Rightarrow x=2017\)