这种题目有2个未知数,但只一个方程,一般要用配方法解.x^2 + y^2 - x - 6y + 9.25 = 0x^2- x + 0.25 + y^2 - 6y + 9 = 0(x - 0.5)^2 +(y - 3)^2 = 0x = 0.5y = 3