已知x2-6x+8y+y2+25=0,求2x+3y的值
问题描述:
已知x2-6x+8y+y2+25=0,求2x+3y的值
答
x2-6x+8y+y2+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
2x+3y=6-12=-6