若y2+4y+4+x+y−1=0,则xy的值为_.
问题描述:
若y2+4y+4+
=0,则xy的值为______.
x+y−1
答
∵y2+4y+4+
=0
x+y−1
∴(y+2)2+
=0
x+y−1
∴y+2=0或x+y-1=0
解得:y=-2,x=3
则xy的值为3-2=
.1 9
故答案是:
.1 9