已知4x2+y2-4x+10y+26=0,求6x-1/5y的值.
问题描述:
已知4x2+y2-4x+10y+26=0,求6x-
y的值. 1 5
答
∵4x2+y2-4x+10y+26=4(x-
)2+(y+5)2=0,1 2
∴x=
,y=-5,1 2
则原式=3+1=4.