The first equation is that of a circle.
The second equation is that of a line.
A line can intersect a circle in at most two points.
Answer: (b) 2
Edwin
One equation is a circle, and the other is a straight line. A circle and a straight line can intersect in 0, 1, or 2 points. The two particular equations that you provided do, in fact, intersect in two points.
A more general question and one that would better illustrate the concept that I think your instructor was trying to communicate would be:
What is the greatest number of solutions to the following system of equations:
where is any real constant > 0.
The answer is the same, but the general case illustrates all three possibilities.
John
My calculator said it, I believe it, that settles it