Can you guys help me with these questions?

20 points! asap! a is known to be 6,500 feet above sea level; ab = 600 feet. the angle at a looking up at p is 20°. the angle at b looking up at p is 35°. how far above sea level is the peak p? find the height of the mountain peak to the nearest foot. height above sea level =

[10 points, algebra 2-simplifying complex fractions]according to my answer key the restrictions are -1 and 4. but why not positive 1?

What is coefficient of the term of degree of degree 5 in the polynomial below