# How do you find the center (h,k) and radius r of the circle with the given equation #x^2+y^2-18x+18y=-137#?

##### 1 Answer

Jan 20, 2016

The centre is

#### Explanation:

The equation needs to be rearranged into the form

First reorder the expression to group the

Each group then needs to be expressed as a square by completing the squares

The circle is then

The centre is therefore