Ta có: \(\frac{2-x}{2007}-1=\frac{1-x}{2008}-\frac{x}{2009}\)

=>\(\frac{2-x}{2007}=\frac{1-x}{2008}-\frac{x}{2009}+1\)

=>\(\frac{2-x}{2007}=\left(\frac{1-x}{2008}+1\right)-\frac{x}{2009}+1-1\)

=>\(\frac{2-x}{2007}+1=\frac{1-x+2008}{2008}+\left(1-\frac{x}{2009}\right)\)

=>\(\frac{2-x+2007}{2007}=\frac{2009-x}{2008}+\frac{2009-x}{2009}\)

=>\(\frac{2009-x}{2007}=\frac{2009-x}{2008}+\frac{2009-x}{2009}\)

=>\(\frac{2009-x}{2007}-\frac{2009-x}{2008}-\frac{2009-x}{2009}=0\)

=>\(\left(2009-x\right).\left(\frac{1}{2007}-\frac{1}{2008}-\frac{1}{2009}\right)=0\)

Vì \(\frac{1}{2007}-\frac{1}{2008}-\frac{1}{2009}\ne0\)

=>2009-x=-

=>x=2009

Vậy tập nghiệm của phương trình S=2009

Lê Chí Cường nhầm đoạn cuối rồi kìa

\(\frac{2-x}{2007}-1=\frac{1-x}{2008}-\frac{x}{2009}\)

\(\Leftrightarrow\frac{2-x}{2007}+1=\frac{1-x}{2008}+1-\frac{x}{2009}+1\)

\(\Leftrightarrow\frac{2009-x}{2007}=\frac{2009-x}{2008}-\frac{2009-x}{2009}\)

\(\Leftrightarrow\frac{2009-x}{2007}-\frac{2009-x}{2008}-\frac{2009-x}{2009}=0\)

\(\Leftrightarrow\left(2009-x\right)\left(\frac{1}{2007}-\frac{1}{2008}-\frac{1}{2009}\right)=0\)

mà \(\frac{1}{2007}-\frac{1}{2008}-\frac{1}{2009}\ne0\)

nên phương trình trên \(\Leftrightarrow2009-x=0\Leftrightarrow x=2009\)

\(\frac{x}{2008}+\frac{x+1}{2009}+...+\frac{x+4}{2012}=5\)

\(\Leftrightarrow\left(\frac{x}{2008}-1\right)+\left(\frac{x+1}{2009}-1\right)+...+\left(\frac{x+4}{2012}-1\right)=0\)

\(\Leftrightarrow\frac{x-2008}{2008}+\frac{x-2008}{2009}+...+\frac{x-2008}{2012}=0\)

\(\Leftrightarrow\left(x-2008\right)\left(\frac{1}{2008}+\frac{1}{2009}+..+\frac{1}{2012}\right)=0\)

Mà \(\left(\frac{1}{2008}+\frac{1}{2009}+..+\frac{1}{2012}\right)\ne0\)

Nên \(x-2008=0\)

\(\Leftrightarrow x=2008\)

Vậy : \(x=2008\)

\(\frac{x}{2008}+\frac{x+1}{2009}+\frac{x+2}{2010}+\frac{x+3}{2011}+\frac{x+4}{2012}=5\)

\(\Leftrightarrow\frac{x}{2008}+\frac{x+1}{2009}+\frac{x+2}{2010}+\frac{x+3}{2011}+\frac{x+4}{2012}-5=0\)

\(\Leftrightarrow\left(\frac{x}{2008}-1\right)+\left(\frac{x+1}{2009}-1\right)+\left(\frac{x+2}{2010}-1\right)+\left(\frac{x+3}{2011}-1\right)+\left(\frac{x+4}{2012}-1\right)=0\)

\(\Leftrightarrow\frac{x-2008}{2008}+\frac{x-2008}{2009}+\frac{x-2008}{2010}+\frac{x-2008}{2011}+\frac{x-2008}{2012}=0\)

\(\Leftrightarrow\left(x-2008\right)\left(\frac{1}{2008}+\frac{1}{2009}+\frac{1}{2010}+\frac{1}{2011}+\frac{1}{2012}\right)=0\)

Vì \(\frac{1}{2008}+\frac{1}{2009}+\frac{1}{2010}+\frac{1}{2011}+\frac{1}{2012}\ne0\)

\(\Rightarrow x-2008=0\)\(\Leftrightarrow x=2008\)

Vậy \(x=2008\)

\(x=2009\)

\(\Rightarrow x-1=2008\left(1\right)\)

Thay (1) vào A ta được:

\(A=x^{2009}-2008x^{2008}-2008x^{2007}-...-2008x+1\)

\(A=x^{2009}-\left(x-1\right)x^{2008}-...-\left(x-1\right)x+1\)

\(A=x^{2009}-x^{2009}+x^{2008}-...-x^2-x+1\)

\(A=-x+1\)

\(A=-2009+1\)

\(A=-2008\)

Có ai giúp mình làm ko?

Lộn đề

\(A=x^{2009}-2008x^{2008}-2008x^{2007}-...-2008x+1\)1

Lộn đề tiếp\

\(A=x^{2009}-2008x^{2008}-2008x^{2007}-....2008x+1\)

Để PT có nghiệm khi \(2009y^{2010}\) lẻ \(\Rightarrow y^{2010}\)lẻ Hay \(y\) lẻ

\(\Rightarrow y^2\equiv1\left(mod4\right)\)\(\Rightarrow2009y^{2010}\equiv1\left(mod4\right)\)

Mà \(2008x^{2009}\equiv0\left(mod4\right)\) nên \(2008x^{2009}+2009y^{2010}\equiv1\left(mod4\right)\)

Mà \(2011\equiv3\left(mod4\right)\) 

\(\Rightarrow2008x^{2009}+2009y^{2010}\ne2011\forall x;y\in Z\)

Vậy PT vô nghiệm nguyên