若x^2+4y^2+2x-4y+2=0,求5x^2+16y^2的算术平方根.

若x^2+4y^2+2x-4y+2=0,求5x^2+16y^2的算术平方根.
若x^2+4y^2+2x-4y+2=0,求5x^2+16y^2的算术平方根.

若x^2+4y^2+2x-4y+2=0,求5x^2+16y^2的算术平方根.
x^2+4y^2+2x-4y+2=0
x^2+2x+1+4y^2-4y+1=0
(x+1)^+(2y-1)^2=0
x+1=0 x=-1
2y-1=0 y=1/2
5x^2+16y^2
=5+16(1/2)^2
=5+4
=9
√9=3

x=-1,y=1/2;
带进去算出来等于3