Given the center
and the radius
of a circle, its equation is

In your case, the center is (-4,0), and the radius is 2. Plug these values into the generic formula and you'll get the equation.
Answer:
13.5
Step-by-step explanation:
Step-by-step explanation:

Answer:
$6.75 dollars
Step-by-step explanation:
Here is the equation:

⇒

You need to get "x" by itself so minus 3 from each side

⇒

⇒

Divide 8 by 2

÷

x=4
So each 4 is equivalent to 4
Lets check:

⇒

⇒

So that means that Marcus practiced the piano for 4 hours and Donnel practiced for 7