2007^2/(2006^2+2008^-2)
=2007^2*2008^2/(2006^2*2008^2+1)
=2007^2*2008^2/[(2007-1)-(2007-1)+1]
= 2007^2*2008^2/[(2007^2-1+1]
= 2007^2*2008^2/(2007^2)
=2008^2
=4032064
2007^2/(2006^2+2008^-2)
=2007^2*2008^2/(2006^2*2008^2+1)
=2007^2*2008^2/[(2007-1)-(2007-1)+1]
= 2007^2*2008^2/[(2007^2-1+1]
= 2007^2*2008^2/(2007^2)
=2008^2
=4032064