What is the center and radius of the circle with equation(x+1)2+y2=81?

question 1 options:

center: (1,0) ; radius: 81

center: (-1,0) ; radius: 81

center: (-1,0) ; radius: 9

center: (1,0) ; radius: 9

center: (-1,0) ; radius: 9

Step-by-step explanation:

we know that

The equation of a circle in center radius form is equal to

where

(h,k) is the center of the circle

r is the radius of the circle

In this problem we have

so

The center (h,k) is the point  

and

the radius

therefore

center: (-1,0) ; radius: 9

the answer is a

step-by-step explanation:

because if you put 1 in to the square root of x it equals 300.