Research department, 8 employees, budget of $11,500

All per-unit concepts rely on ratios,meaning,to provide a type of measurement

!! 10 ! a westbound jet leaves central airport traveling 635 miles per hour. at the same time, an eastbound plane departs at 325 miles per hour. in how many hours will the planes be 1900 miles apart?

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.