由x+y=6得y=6-x,代入xy=5得(6-x)x=5整理得x^2-6x+5=0解得x=1或x=5当x=1时，y=5,x^2-y^2=1-25=-24当x=5时，y=1,x^2-y^2=25-1=24所以，x^2-y^2的值为±24
