(8+3)n for n=6 help me please I'm not sure how to answer this problem how do I work this problem to get answer?

Solve the equation: x - 9 = -6 + 5 a. 21 b. 7 c. 14 d. 2

Select the correct answer and solve for y

Alice is paying her bill at a restaurant. but tax on the cost of a male is 5%. she decides to leave a tip 20% of the cost of the meal plus the tax