若x^2-6x+y^2+8y+25=0,则x=多少,y=多少
问题描述:
若x^2-6x+y^2+8y+25=0,则x=多少,y=多少
答
若x^2-6x+y^2+8y+25=0,则x=3,y=-4
x²-6x+y²+8y+25=0
x²-6x+9+y²+8y+16=0
(x-3)²+(y+4)²=0
x-3=0 y+4=0
∴x=3 y=-4