方程(2008x)²+2007×2009x=1
(2008x)²+(2008-1)×(2008+1)x=1
(2008x)²+(2008^2-1)x-1=0
2008^2x(x+1)-(x+1)=0
(x+1)(2008^2x-1)=0
x=-1或x=1/2008^2
-4x²-y²+4x-6y-11
=-(4x^2-4x+1)-(y^2+6y+9)-1
=-(2x-1)^2-(y+3)^2-1