Calc based physics spring problem

[isaacsquared]

1. A force of 10 N holds an ideal spring with a spring constant of 20 N/m in compression. The potential energy stored in the spring is what?



2. F=kx



3. I really am stumped. If I had the length of the spring then it'd be easy peasy (well... it still probably is. What am I missing?)

 

[gabbagabbahey]

Hint- What does the $$x$$ in $$F=kx$$ represent?

What is the equation for the potential energy of a spring?