Please help me with this I don’t know how.

Write the rational number in lowest terms 99/-15

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)

Someone answer asap for ! the total ticket sales for a high school basketball game were $2,260. the ticket price for students were $2.25 less than the adult ticket price. the number of adult tickets sold was 230, and the number of student tickets sold was 180. what was the price of an adult ticket?