# The equation of a circle is (x + 10)^2 + (y - 4)^2 = 100. What is the center and radius of the circle?

Mar 18, 2018

Center is $\left(- 10 , 4\right)$ andradius is $10$.

#### Explanation:

If the center of circle is $\left(h , k\right)$ and its radius is $r$, equatiion of circle is

${\left(x - h\right)}^{2} + {\left(y - k\right)}^{2} = {r}^{2}$

Here equation of circle is ${\left(x + 10\right)}^{2} + {\left(y - 4\right)}^{2} = 100$ can be written as

${\left(x - \left(- 10\right)\right)}^{2} + {\left(y - 4\right)}^{2} = {10}^{2}$

Hence, center is $\left(- 10 , 4\right)$ andradius is $10$.

graph{((x+10)^2+(y-4)^2-100)((x+10)^2+(y-4)^2-0.2)=0 [-30.5, 13.5, -7.4, 14.6]}