Question 135958
The specific values of the points for each of the curves is not important. 
This is more of a "think-about-it" question. 
What can you say about f(x) and g(x) when f(x)-g(x)=0?
{{{f(x)-g(x)=0}}}
{{{f(x)=g(x)}}}
Whenever the two curves intersect (when f=g), the difference function has a zero. 
Add up the number of intersections, that's the number of zeros for the difference function.