The circle with center (1,5) and radius 4 has equation

Look at the following graph of the given equation. determine whether the equation is a function. explain why or why not.

If, while training for a marathon, you ran 60 miles in 2/3 months, how many miles did you run each month? (assume you ran the same amount each month) write your answer as a whole number, proper fraction, or mixed number in simplest form. you ran __ miles each month.

How many solutions does the nonlinear system of equations graphed below have?