Hellp select all the right ones

How do you use the elimination method for this question? explain, because i really want to understand!

Henry is an avid reader, he devours 90 pages in half an hour how many pages has henry read per minute?

1. a parachutist is 800 feet above the ground when she opens her parachute. she then falls at a constant rate of 5 feet per second. select the equation that represents this situation. h = -800t + 5 y = -5x + 800 h = 5t - 800 y = 800x + 5 i need