\(\frac{x+1}{2010}+\frac{x+2}{2009}+\frac{x+3}{2008}+...+\frac{x+2010}{1}=\left(-2010\right)\)

\(\Rightarrow\left(\frac{x+1}{2010}+1\right)+\left(\frac{x+2}{2009}+1\right)+...+\left(\frac{x+2010}{1}+1\right)=-2010+2010\)

\(\Rightarrow\frac{x+2011}{2010}+\frac{x+2011}{2009}+...+\frac{x+2011}{1}=0\)

\(\Rightarrow\left(x+2011\right)\left(1+\frac{1}{2}+...+\frac{1}{2009}+\frac{1}{2010}\right)=0\)

\(\Rightarrow x+2011=0\Leftrightarrow x=-2011\)

x=-2011

\(\frac{x-1}{2009}+\frac{x-2}{2010}=\frac{x+5}{2003}+\frac{x+7}{2001}\)

\(\Leftrightarrow\frac{x-1}{2009}+1+\frac{x-2}{2010}+1=\frac{x+5}{2003}+1+\frac{x+7}{2001}+1\)

\(\Leftrightarrow\frac{x-1}{2009}+\frac{2009}{2009}+\frac{x-2}{2010}+\frac{2010}{2010}=\frac{x+5}{2003}+\frac{2003}{2003}+\frac{x+7}{2001}+\frac{2001}{2001}\)

\(\Leftrightarrow\frac{x+2008}{2009}+\frac{x+2008}{2010}=\frac{x+2008}{2003}+\frac{x+2008}{2001}\)

\(\Leftrightarrow\frac{x+2008}{2009}+\frac{x+2008}{2010}-\frac{x+2008}{2003}-\frac{x+2008}{2001}=0\)

\(\Leftrightarrow\left(x+2008\right)\left(\frac{1}{2009}+\frac{1}{2010}-\frac{1}{2003}-\frac{1}{2001}\right)=0\)

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

Cộng mỗi p/s thêm 1 bạn nhé :)

1. \(\left(2x-1\right)^3+\left(x+2\right)^3=\left(3x+1\right)^3\)

\(\Rightarrow8x^3-12x^2+6x-1+x^3+6x^2+12x+8=27x^3+27x^2+9x+1\)

\(\Rightarrow-18x^3-33x^2+9x+6=0\)\(\Rightarrow\left(x+2\right)\left(-18x^2+3x+3\right)=0\)

\(\Rightarrow\left(x+2\right)\left(2x-1\right)\left(-9x-3\right)=0\Rightarrow\orbr{\begin{cases}x=-2\\x=\frac{1}{2};x=-\frac{1}{3}\end{cases}}\)

Vậy \(x=-2;x=\frac{1}{2};x=-\frac{1}{3}\)

2. \(\frac{x-1988}{15}+\frac{x-1969}{17}+\frac{x-1946}{19}+\frac{x-1919}{21}=10\)

\(\Rightarrow\left(\frac{x-1988}{15}-1\right)+\left(\frac{x-1969}{17}-2\right)+\left(\frac{x-1946}{19}-3\right)+\left(\frac{x-1919}{21}-4\right)=0\)

\(\Rightarrow\frac{x-2003}{15}+\frac{x-2003}{17}+\frac{x-2003}{19}+\frac{x-2003}{21}=0\)

\(\Rightarrow x-2003=0\)do \(\frac{1}{15}+\frac{1}{17}+\frac{1}{19}+\frac{1}{21}\ne0\)

Vậy \(x=2003\)

3. Đặt \(\hept{\begin{cases}2009-x=a\\x-2010=b\end{cases}}\)

\(\Rightarrow\frac{a^2+ab+b^2}{a^2-ab+b^2}=\frac{19}{49}\Rightarrow49a^2+49ab+49b^2=19a^2-19ab+19b^2\)

\(\Rightarrow30a^2+68ab+30b^2=0\Rightarrow\left(5a+3b\right)\left(3a+5b\right)=0\)

\(\Rightarrow\orbr{\begin{cases}5a=-3b\\3a=-5b\end{cases}}\)

Với \(5a=-3b\Rightarrow5\left(2009-x\right)=-3\left(x-2010\right)\)

\(\Rightarrow-2x=-4015\Rightarrow x=\frac{4015}{2}\)

Với \(3a=-5b\Rightarrow3\left(2009-x\right)=-5\left(x-2010\right)\)

\(\Rightarrow2x=4023\Rightarrow x=\frac{4023}{2}\)

Vậy \(x=\frac{4023}{2}\)hoặc \(x=\frac{4015}{2}\)

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

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

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

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

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

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

mà 1/2011+1/2010-1/2009-1/2008 khác 0 

\(\Rightarrow x+2012=0\Rightarrow x=-2012\)

\(\left(3x-2\right)^2-x\left(9x-2\right)=24\Leftrightarrow9x^2-12x+4-9x^2+2x=24\)

\(\Leftrightarrow-10x+4=24\Leftrightarrow-10x=20\Leftrightarrow x=-2\)

1;  Ta có : x+1/2011 + x+2/2010 = x+3/2009 + x+4/ 2008

Suy ra: 2+(x+1/2011 + x+2/2010 ) = 2+( x+3/2009 + x+4/2008)

suy ra ban tach 2=1+1 roi cong 1 voi  tưng phân số  trên nha  sẽ ra kết quả ngay thôi 

2; gợi ý nè : (3x-2)^2 =(3x)^2 + 2*3x*2+2^2

Bài này đề sai thì phải ??

X=2012.

100% bằng 2012

pt <=> (2-x/2009 + 1) = (1-x/2010 + 1) + (1 - x/2011)

<=> 2011-x/2009 = 2011-x/2010 + 2011-x/2011

<=> 2011-x/2009 - 2011-x/2010 - 2011-x/2011 = 0

<=> (2011-x).(1/2009-1/2010-1/2011) = 0

<=> 2011-x=0 ( vì 1/2009-1/2010-1/2011 khác 0 )

<=> x=2011

Vậy x=2011

Tk mk nha

Trả lời :

          Bạn kia trả lời đúng rồi !

Hok tốt nha !

Ta có pt <=> \(2\sqrt{x-2}+2\sqrt{y+2009}+2\sqrt{z-2010}=x+y+z\)

<=> \(x-2-2\sqrt{x-2}+1+y+2009-2\sqrt{y+2009}+1+z-2010-2\sqrt{z-2010}+1=0\)

<=> \(\left(\sqrt{x-2}-1\right)^2+\left(\sqrt{y+2009}-1\right)^2+\left(\sqrt{z-2010}-1\right)^2=0\)

...

^_^

nát cả óc!

\(\frac{x-2009-2010}{2008}+\frac{x-2008-2010}{2009}+\frac{x-2008-2009}{2010}=3\)

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

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

\(\Leftrightarrow x-6027=0\Leftrightarrow x=6027\)