问答题
x2-4xy+4y2+8y+3=0
问答题x2-4xy+4y2+8y+3=0
5x2+8xy+5y2-18x-18y+9=0
问答题5x2+8xy+5y2-18x-18y+9=0
x2+2xy+y2-8x+4=0
问答题x2+2xy+y2-8x+4=0