x²+y²-8x-10y+41=0x²-8x+16+y²-10y+25=0(x-4)²+(y-5)²=0平方项恒非负,两平方项之和=0,两平方项均=0x-4=0 x=4y-5=0 y=5y/(x²-xy)+x/(y²-xy)=y/[x(x-y)]-x/[y(x-y)]=(y²...