Brett is 75 feet from the base of a building. he measures the angle of elevation to the top of the building and records it as 80 degrees. if each story of the building is 17 feet how many floors does the building have

This is the concept of trigonometry, we are required to calculate the number of floors the building has given the information above;
# floors=[height of the building]/[height of each floor]
height of each floor=17 ft
let the height of the building be,h.
h is given by;
tan theta=opposite/adjacent
theta=80
opposite=h
adjacent=75 ft
thus
tan 80=h/75
h=75 tan 80
h=425.35 ft
thus the number of floors will be:
425.35/17
=25.020≈25 floors

I’m not positive but i think it’s none of your buisness

First subtract 10 from both side
y^2+6y-16=0
(y+8)(y-2)=0
-8 and 2