Compute the following problems:
Problem I:

Part A: How long does it take the astronaut to travel 4.30 ly at 0.99944c (as measured by the Earth-bound observer)?

Part B: How long does it take according to the astronaut?

Problem II: You measure the length of a spaceship at rest relative to you to be 500 m,

Part A: how long will an observer measure it to be if the observer lies past the spaceship at 0.75c?

Please clarify the equations and steps are used to get the solutions. Thanks!