1, tìm x biết 2011-|x-2011|=x
1,tìm x,y biết:
x-2011/12+x-2011/20+x-2011/30+x-2011/42+x-2011/56+x-2011/72=16/9
Tìm x biết :
( x - 2011)x+1 - ( x - 2011 )x+2011 = 0
Đặt (x-2011)^x ra ngoài . Làm tương tự như bài lúc nãy nhé.
Tìm x biết :
( x - 2011)x+1 - ( x - 2011 )x=2011 = 0
\(\left(x-2011\right)^{x+1}-\left(x-2011\right)^{x+2011}=0\)
\(\Rightarrow\left(x-2011\right)^{x+1}.\left(1-x^{2010}\right)=0\)
\(\Rightarrow\left[\begin{array}{nghiempt}\left(x-2011\right)^{x+1}=0\\1-x^{2010}=0\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}x=2011\\x=\pm1\end{array}\right.\)
Vậy x = 2011 ; x = 1 ; x = - 1
Tìm x biết
\(\left(x-2011\right)^{x+1}-\left(x-2011\right)^{x+2011}=0\)
Ta cÓ : ( x - 2011) x+ 1 - ( x - 2011)x + 2011
=) x - 2011= 0 =) x = 2011
Tìm x biết : 2011 . | x - 2011 | + ( x - 2011 )\(^2\)= 2013 . | 2011 - x |
\(\Leftrightarrow2011.\left|x-2011\right|+\left(x-2011\right)^2=2013.\left|x-2011\right|\)
\(\Leftrightarrow\left(x-2011\right)^2=2.\left|x-2011\right|\Rightarrow\orbr{\begin{cases}x-2011=0\\2=\left|x-2011\right|\end{cases}}\Rightarrow\orbr{\begin{cases}x=2013\\x=2009\end{cases}}\text{hoặc }x=2011\)
Vậy ....
Tìm n biết: (x-3)+(x-2)+(x-1)+...+9+10+2011=2011
Tìm số hữu tỉ x biết:
a) \(\frac{x+4}{2009}+\frac{x+3}{2010}=\frac{x+2}{2011}+\frac{x+1}{2012}\)
b) \(\frac{x-2011}{2010}+\frac{x-2011}{2011}+\frac{x-2011}{2012}=\frac{x-2011}{2013}+\frac{x-2011}{2014}\)
a) \(\frac{x+4}{2009}+1+\frac{x+3}{2010}+1=\frac{x+2}{2011}+1+\frac{x+1}{2012}\)
\(\frac{x+4+2009}{2009}+\frac{x+3+2010}{2010}=\frac{x+2+2011}{2011}+\frac{x+2+2012}{2012}\)
\(\frac{x+2013}{2009}+\frac{x+2013}{2010}-\frac{x+2013}{2011}-\frac{x+2013}{2012}=0\)
\(\left(x+2013\right).\left(\frac{1}{2009}+\frac{1}{2010}-\frac{1}{2011}-\frac{1}{2012}\right)=0\) (1)
Vì \(\left(\frac{1}{2009}+\frac{1}{2010}-\frac{1}{2011}-\frac{1}{2012}\right)\ne0\)
Nên biểu thức (1) xảy ra khi \(x+2013=0\)
\(x=-2013\)
b) \(\left(x-2011\right)\left(\frac{1}{2010}+\frac{1}{2011}+\frac{1}{2012}-\frac{1}{2013}-\frac{1}{2014}\right)=0\) (2)
Vì \(\left(\frac{1}{2010}+\frac{1}{2011}+\frac{1}{2012}-\frac{1}{2013}-\frac{1}{2014}\right)\ne0\)
Nên biểu thức (2) xảy ra khi \(x-2011=0\)
\(x=2011\)
Tìm số tự nhiên x biết:
X×2011-x=2011×2009+2011
X x 2011-X=2011x2009+2011
Xx(2011-1)=2011x(2009+1)
Xx2010 = 2011x2010
=> X=2011
x * 2011 - x = 2011 x 2009 + 2011
x * ( 2011 - 1 ) = 2011 x ( 2009 + 1 )
x * 2010 = 2011 x 2010
x = 2011
Tìm số nguyên x biết
a . 2011 − | x | = 2009 b . | x − 5 | + 9 = 2011