已知x2+y2-4x+8y+20=0则x+y的值为多少?
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/11 10:21:45
![已知x2+y2-4x+8y+20=0则x+y的值为多少?](/uploads/image/z/8565645-21-5.jpg?t=%E5%B7%B2%E7%9F%A5x2%2By2-4x%2B8y%2B20%3D0%E5%88%99x%2By%E7%9A%84%E5%80%BC%E4%B8%BA%E5%A4%9A%E5%B0%91%3F)
x){}K++tM*-*l
v̬Ю|>iÞ';v=]2醉6IEi/!Î
5eCskJ N LHBF&TJRF2D@($dkSikqv-ŶF6yv Ufvq
已知x2+y2-4x+8y+20=0则x+y的值为多少?
已知x2+y2-4x+8y+20=0则x+y的值为多少?
已知x2+y2-4x+8y+20=0则x+y的值为多少?
x²+y²-4x+8y+20=0
则x²-4x+4+y²+8y+16=0
则(x-2)²+(y+4)²=0
则x-2=0,y+4=0
则x=2,y=-4
x+y=2-4=-2