(2009 x 2010 + 2011 x 12 + 1998)/(2011 x 2010 - 2010 x 2009)
so sánh
2009 x 2011 và 2010 x 2010
2010 x 2007 và 2005 x 2009
2011 x 1998 và 1996 x 2000
2012 x 2000 và 1990 x 2010
2009 . 2001 < 2010 .2010 2010 .2007 > 2005. 2009 2011.1998 > 1996.2000 2012. 2000> 2010. 1990 dấu chấm là dấu nhân cho mik k đi ban mik cm
\(\frac{x-2010-2011}{2009}\)+\(\frac{x-2009-2011}{2010}\)+\(\frac{x-2009-2010}{2011}\)= 3
lấy cả 2 vế trừ đi 3
\(\frac{x-2010-2011}{2009}+\frac{x-2009-2011}{2010}+\frac{x-2009-2010}{2011}=3\)
\(\Leftrightarrow\left(\frac{x-2010-2011}{2009}-1\right)+\left(\frac{x-2009-2011}{2010}-1\right)+\left(\frac{x-2009-2010}{2011}-1\right)=0\)
\(\Leftrightarrow\frac{x-6030}{2009}+\frac{x-6030}{2010}+\frac{x-6030}{2011}=0\)
\(\Leftrightarrow\left(x-6030\right)\left(\frac{1}{2009}+\frac{1}{2010}+\frac{1}{2011}\right)\)
\(\Leftrightarrow x-6030=0\)(vì \(\frac{1}{2009}+\frac{1}{2010}+\frac{1}{2011}>0\))
\(\Leftrightarrow x=6030\)
Vậy ................
2011 x 2010 - 1/2009 x 2011 + 2010
`(2011xx2020-1)/(2009xx2011+2010)`
`=((2009+1)xx2011-1)/(2009xx2011+2010)`
`=(2009xx2011+2011-1)/(2009xx2011+2010)`
`=(2009xx2011+2010)/(2009xx2011+2010)`
`=1`
\(\dfrac{2011.2010-1}{2009.2011+2010}\)
= \(\dfrac{2011.2009+2011-1}{2009.2011+2010}\)
= \(\dfrac{2011.2009+2010}{2009.2011+2010}\)
= 1
( 2009/2010 + 2010/2011 + 2011/2012 ) x ( 1/3 - 1/4 - 1/12 )
Tìm các số nguyên x,y thỏa mãn:
\(x^{2009}+x^{2010}+2009^{2010}=y^{2010}+y^{2011}+2010^{2011}\)
tim x y z
\(\left|x-2009\right|^{2009}+\left(y-2010\right)^{2010}+2011\left|z-2011\right|\le0\)
Ta có: /x-2009/2009\(\ge\)0; (y-2010)2010=[(y-2010)1005]2 \(\ge\)0 và 2011/z-2011/\(\ge\)0
Tổng 3 số dương 0 khi và chỉ khi 3 số đó đều=0, khi đó dấu bằng xảy ra.
=> \(\hept{\begin{cases}Ix-2009I^{2009}=0\\\left(y-2010\right)^{2010}=0\\2011Iz-2011I=0\end{cases}}\)
=> x=2009; y=2010; z=2011
Tìm x biết : 2011 + 2010+2009+...+x=2011
2011+2010+2009+...+x=2011
Giải pt :\(\frac{\sqrt{x-2009}-1}{x-2009}+\frac{\sqrt{y-2010}-1}{y-2010}+\frac{\sqrt{z-2011}-1}{z-2011}=\frac{3}{4}\)