Solve for the angle y

What is the prime factorization of 195

Rob spent 25%, percent more time on his research project than he had planned. he spent an extra h hours on the project. which of the following expressions could represent the number of hours rob actually spent on the project? two answers

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