Solve the all parts of given question:
Question: A particle moves along the x-axis. Its position varies with time according to the expression x(t) = -6t + 5t2, where x is in meters and t is in seconds.
Part A: Determine the displacement of the particle in the two time intervals t = 0 to t = 1 s and t = 1 s to t = 4 s.
Part B: Calculate the average velocity during these two time intervals.
Part C: Find the instantaneous velocity of the particle at t = 2.5 s.
Please help, completely confused!! Give steps if possible for above problem.