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:

Step-by-step explanation:
Let
c -----> the additional amount (in dollars) David will spend
we know that
The word " at most" in this context means "less than or equal to"
The amount David has spent plus possible additional amounts he will spend must be less than or equal to $39
so
The inequality that represent this situation is

solve for c
subtract 22 both sides


The maximum amount he could spend is $17
Answer:
A clinical test on humans of a new drug is normally done in three phases. Phase I is conducted with a relatively small number of healthy volunteers. For example, a phase I test of a specific drug involved only 7 subjects.
Step-by-step explanation:
The standard form of the equation of a circle is:

Where the point (a,b) represents the centre and r is the radius. So, given your information, the equation will be: