Physics Hooke's Law Problem

A Hooke's law spring has a spring constant of 10,000 N/m. How far must the spring be compressed from its equilibrium position to store 100 J of potential energy?

p.e = (1/2)*k*x^2 = 100 J
k = 1e4 N/m
Solve for x.

F = - k x
=> 100 = - 10000 * x
=> x = - 0.01 m = - 1 cm

Spring should be compressed by 1 cm from its equilibrium position.