x^2+2x+1+4y^2-4y+1=0即(x+1)^2+(2y-1)^2=0x+1=0 2y-1=0x=-1 y=0.55x2＋16y2=5+4=9算数平方根为3
x2+4y2+2x-4y+2=0(x+1)2+(2y-1)2=0x+1=0 x=-12y-1=0 y=1/25x2+16y2=5+4=9算数平方根=3
