# How do you find the center and radius of the circle: # x^2 + y^2 – 10x + 6y + 18 = 0#?

##### 2 Answers

Centre is

#### Explanation:

We must write this equation in the form

Where

So the equation is

Complete the squares so add 25 on both sides of the equation

=

Now add 9 on both sides

=

This becomes

So we can see that the centre is

**centre** :

**radius** :

#### Explanation:

**The general equation of a circle:**

whose **centre** is **radius** is

We have,

Comparing with

So,

radius

i.e.

centre

i.e. centre