Chapter 1 - Section 1.9 - Distance and Midpoint Formulas; Circles - Exercise Set - Page 280: 67

See graph. $(0,-4)$ and $(4,0)$. See explanations.

Step 1. See graph. Step 2. We can find the intersections as $(0,-4)$ and $(4,0)$. Step 3. With the original equations, plug-in the coordinates; we have $(0)^2+(-4)^2=16, (0)-(-4)=4$ and $(4)^2+(0)^2=16, (4)-(0)=4$