tớ có sửa đề nha
\(\dfrac{2004\times2006-2003}{2005\times2005-2004}\\ =\dfrac{\left(2005-1\right)\times\left(2005+1\right)-2003}{2005\times2005-2004}\\ =\dfrac{2005\times2005+2005-2005-1-2003}{2005\times2005-2004}\\ =\dfrac{2005\times2005-2004}{2005\times2005-2004}\\ =1\)