x²+y²-8xy=0所以x²+y²=8xyx²+2xy+y²=10xy(x+y)²=10xyx²+y²=8xyx²-2xy+y²=6xy(y-x)²=6xy所以(x+y)²/(y-x)²=10xy/6xy=5/3x>0,y>0所以x+y>0x>y...