Answer:
Step-by-step explanation:
x^2 + y^2 = 9, or x^2 + y^2 = 3^2, is the equation of a circle with center at (0, 0) and radius 2. It does not represent a line such as y = mx + b.
If you were given both x^2 + y^2 = 9 and y = mx + b, you could find zero, or one, or two points of intersection between circle and line.
x^2 + y^2 = 9 could be solved for either x or y as follows:
x^2 = 9 - y^2, so that x = ±√(9 - y^2). This is valid for 0 ≤ y < infinity, but again we have not "solve in y = mx + b" format.