On graph paper, graph the equations below. For each one, name the center and radius.

1. $x^2 + y^2 = 4.5^2$

   Hint (a):

   The general equation for a circle with a center at the origin is $x^2 + y^2 = r^2$.

2. $x^2 + y^2 = 75$

   Hint (b):

   $\sqrt{ 75 } \, \approx \, 8.66$

3. $(x − 3)^2 + y^2 = 1$

4. $x^2 − 4x + y^2 − 2y = 14$