设圆心是(a,0)得
(a-5)²+1²=(a-1)²+3²
a²-10a+25+1=a²-2a+1+9
-10a+2a=10-26
-8a=-16
a=2
半径r=√[(2-5)²+1²]=√10
∴方程是(x-2)²+y²=10