Physics (Gradient, Energy, Force)

The force in a spring is given by the equation Fs = -kx, where"k" is the spring constant (how stretchy a spring is), and x is how far the spring is compressed or stretched. 

a. Write a differential equation that relates the change of the energy stored in a spring to the force needed to stretch or compress it.

b. Solve this equation to find the energy in terms of the spring constant and the stretch/compress distance.

Thanks in advance​

I had already posted this question but I got no answer so I'm putting it again so maybe someone who knows can help me