The correct answer to this it’s my last question

Omar is going on a road trip! the car rental company offers him two types of cars. each car has a fixed price, but he also needs to consider the cost of fuel. the first car costs $90 to rent, and because of its fuel consumption rate, there's an additional cost of s0.50 per kilometer driven.

Solve the equation x/4 - 5= -8 -27 -12 -7 12

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