已知|x+y-5|+(xy-8)^2=0,则x^2+y^2=?
问题描述：
已知|x+y-5|+(xy-8)^2=0,则x^2+y^2=?
答
因为|x+y-5|+(xy-8)^2=0
所以x+y-5=0,xy-8=0
x+y=5,xy=8
x^2+y^2=(x+y)^2-2xy=25-16=9