algebra precalculus - Difference of 2 roots

$2003^2x^2 - (2002)(2004)x - 1 = 0$

$x^2+2002x - 2003 = 0$

What is the difference of the 1st equation's larger root and the smaller root of the 2nd equation?

I did not know how to approach this, so I used the quadratic formula but could not easily simplify the expressions. What properties will be used ?