解：(1)由题：(x+y)²=16(x+y)²-（x²+y²）=2xy=16-10=6∴xy=6/2=3(2)(x-y)²=(x+y)²-4xy=16-12=4∴x-y=2或-2
xy=((x+y)^2-(x^2+y^2))/2=3x-y=±√（x-y)^2=±√(x+y)^2-4xy=±2
