Answer: The radius of the given circle is 4 units.
Step-by-step explanation: We are given to find the radius of the circle with the following equation :
![x^2+y^2-10x+6y+18=0~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(i)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/jtvuuxj06zwhcl56atpnlh1l64ptskg1na.png)
We know that
the standard equation of a circle with center at the point (h, k) and radius r units is given by
![(x-h)^2+(y-k)^2=r^2.](https://img.qammunity.org/2020/formulas/mathematics/middle-school/a2jf26l0ooqmlglx9jgn4vhkt0m7s7ndyg.png)
From equation (i), we have
![x^2+y^2-10x+6y+18=0\\\\\Rightarrow (x^2-10x+25)+(y^2+6y+9)-25-9+18=0\\\\\Rightarrow (x-5)^2+(y+3)^2-16=0\\\\\Rightarrow (x-5)^2+(y-(-3))^2=4^2.](https://img.qammunity.org/2020/formulas/mathematics/middle-school/a5n7j7dfuh2bmw5qmbosn1wfn7zfwuzsci.png)
Comparing it with the standard equation, the radius of the circle is given by
![r=4.](https://img.qammunity.org/2020/formulas/mathematics/middle-school/mslb8kto0qmwzhnih6mcbfte7fema54zzf.png)
Thus, the radius of the given circle is 4 units.