1.(x^2+4x+4)+(y^2-6y+9)=0
(x+2)^2+(y-3)^2=0
x+2=0,y-3=0
x=-2,y=3
x^y=(-2)^3=-8
2.a^2-ab+1/4b^2=0
(a-1/2b)^2=0
a-1/2b=0
a=1/2b
b/a=2
3.4x-3y=3x-2y或4x-3y=-(3x-2y)
x=y或x=5/7y
x/y=1或x/y=5/7
4.4X^2-8XY+4Y^2
=4(x-y)^2
=4(2^2005+2^2005)^2
=4*(2*2^2005)^2
=4*(2^2006)^2
=2^2*2^4012
=2^4014
5.X^2-Y^2=21
(x+y)(x-y)=21
x+y=3
x-y=7
x=5,y=-2
x^3+12y^3=125+12*(-8)=29