HELP!!

In AMNO, m M = (4x - 13), mZN = (2x – 13), and
m20 = (5x + 19). Find mZN.

Aman is 6 feet 3 inches tall. the top of his shadow touches a fire hydrant that is 13 feet 6 inches away. what is the angle of elevation from the base of the fire hydrant to the top of the man's head?

Acircle has a circumference of 28.36 units what is the diameter of the circle

Factor the expression using the gcf. the expression 21m−49n factored using the gcf