已知实数x,y满足x2+4xy+4y2-x-2y+1/4=0,则x+2y的值为 _ .
问题描述:
已知实数x,y满足x2+4xy+4y2-x-2y+
=0,则x+2y的值为 ___ .1 4
答
已知等式变形得:x2+4xy+4y2-x-2y+
=(x+2y)2-(x+2y)+1 4
=0,1 4
即(x+2y-
)2=0,1 2
∴x+2y-
=0,1 2
则x+2y=
.1 2
故答案为:
1 2