Hi! Could I get some help on part a of this question, please?

(10%) Problem 4: The force required to compress a non-standard spring as a function of displacement from equilibrium x is given by the equation F(x) = ax - bx, where a = 75 N/m , b = 12 N/m, and the positive x direction is in the compression direction of the spring. * 33% Part (a) Write a general equation in terms of the given variables for the work required to compress this spring from equilibrium to any point xp. W = 25 k3 - 6 k2 x Attempts Remain 33% Part (b) Calculate the work done, in joules, on the spring as it is compressed from x = 0 to x1 = 42 cm. WO->1 = 0.7938 Correct! 33% Part (c) Calculate the work done, in joules, on the spring as it is compressed from x 1 = 42 cm to x2 = 86 cm. Grade = 100% Correct Answer Student Final Submission Feedback Not available until end date W1-2 = 10.67 Correct