Solve {l}{(1-x)^{2}+(3-y)^{2}=r^{2}}{(4-x)^{2}+(2-y)^{2}=r^2}{(1-x)^2+(-7-y)^2=r^2}

$$\left. \begin{array} { l } { ( 1 - x ) ^ { 2 } + ( 3 - y ) ^ { 2 } = r ^ { 2 } } \\ { ( 4 - x ) ^ { 2 } + ( 2 - y ) ^ { 2 } = r ^ { 2 } } \\ { ( 1 - x ) ^ { 2 } + ( - 7 - y ) ^ { 2 } = r ^ { 2 } } \end{array} \right.$$

Solve for x, y, r

$$x=1\text{, }y=-2\text{, }r=-5$$

$$x=1\text{, }y=-2\text{, }r=5$$