\(=\dfrac{\left(2005-1\right)\left(2005+2\right)+6}{2005^2+2005+4}\)

\(=\dfrac{2005^2+2005-2+6}{2005^2+2005+4}=1\)

4024037

d) 2005 x 1999 - 1000 x 2005 +2005

2004x2007+6/2005x2005-2009=4020025

\(\frac{2004\times2007+6}{2005\times2005-2009}\)

\(=\frac{4022028+6}{4020025-2009}\)

\(=\frac{4022034}{4018016}.\)

Tham khảo

Ta có:

2004×2007+6

=(2005-1)×2007+6

=2005×2007-2007+6

=2005×(2005+2)-2007+6

=2005×2005+2005×2-2007+6

=2005×2005+4010-2007+6

=2005×2005+9

Vậy 

\(=4022028+6+2009\)

\(=4022034+2099\)

\(=4024043\)

`2007/2009×2002/2005×2009/2006×2005/2007×2006/2002`
`=(2007xx2002xx2009xx2005xx2006)/(2009xx2005xx2006xx2007xx2002)`
`=(2007xx2002xx2009xx2005xx2006)/(2007xx2002xx2009xx2005xx2006)`
`=1`

\(\dfrac{2007}{2009}.\dfrac{2002}{2005}.\dfrac{2009}{2006}.\dfrac{2005}{2007}.\dfrac{2006}{2002}\\ =\left(\dfrac{2007}{2009}.\dfrac{2009}{2006}\right).\left(\dfrac{2006}{2002}.\dfrac{2002}{2005}\right).\dfrac{2005}{2007}\\ =\dfrac{2007}{2006}.\dfrac{2006}{2005}.\dfrac{2005}{2007}=1\)

\(\frac{x+1}{2010}+\frac{x+2}{2009}+\frac{x+3}{2008}=\frac{x+4}{2007}+\frac{x+5}{2006}+\frac{x+6}{2005}\)

<=> \(\frac{x+1}{2010}+1+\frac{x+2}{2009}+1+\frac{x+3}{2008}+1=\frac{x+4}{2007}+1+\frac{x+5}{2006}+1+\frac{x+6}{2005}+1\)

<=> \(\frac{x+2011}{2010}+\frac{x+2011}{2009}+\frac{x+2011}{2008}-\frac{x+2011}{2007}-\frac{x+2011}{2006}-\frac{x+2011}{2005}\) =0

<=> (x+2011).(\(\frac{1}{2010}+\frac{1}{2009}+\frac{1}{2008}-\frac{1}{2007}-\frac{1}{2006}-\frac{1}{2005}\) )=0

<=> x+2011=0

<=> x=-2011

Vậy pt có nghiệm là x=-2011

bằng 4024043 nh k hộ mk nha

bạn ơi. Dấu \ là gì vậy?