Let the Addison's candy count be a and Ronny's be r.
Then a = r - 15. This is an equation.
If you had a second equation, you could replace a with the expression (r - 15), which in itself is not an equation.
Answer: 186
Solution: 100 x 1.86
ANSWER

EXPLANATION
The given expression is

We can see that (x+2) is the greatest common factor.
We factor to obtain;

The correct choice is C.
Equation of circle
(x-h)^2 + (y-k)^2 = r^2
=> (x-10)^2 + (y+4)^2 = 4 is the answer