根据题意有：√(x²+y²)∶√(x-3)²+y²=2:1;√(x²+y²)=2√(x-3)²+y²;x²+y²=4((x-3)²+y²)3x²-24x+3y²+36=0;x²-8x+y²+12=0;(x-4)...