# How do you write the standard from of the equation of the circle given center C(-3, -1) and has a radius of 7?

##### 1 Answer

Sep 19, 2016

#### Explanation:

The standard form of the equation of a circle is.

#color(red)(bar(ul(|color(white)(a/a)color(black)((x-a)^2+(y-b)^2=r^2)color(white)(a/a)|)))#

where (a ,b) are the coordinates of the centre and r, the radius.here a = - 3 , b = - 1 and r = 7

substitute these values into the standard equation.

#(x-(-3))^2+(y-(-1))^2=7^2#

#rArr(x+3)^2+(y+1)^2=49" is the equation"#