问题 填空题

若|x+y-5|+(xy-6)2=0,则x2+y2的值为______.

答案

∵|x+y-5|≥0,(xy-6)2≥0,|x+y-5|+(xy-6)2=0,

∴x+y-5=0,xy-6=0,

∴x+y=5,xy=6,

∴(x+y)2=25,

即x2+y2+2xy=25,

∵xy=6,

∴x2+y2=25-2×6=13.

填空题
单项选择题