How do i get an answer right without writing it down with pencil or paper?

What is the answer to |-2x-5|-|-4+8| and x=7

The krasnapolski is a top-of-the-line hotel in amsterdam, the netherlands. among their many services, they rent bicycles to guests. the bicycle checkout is open 24 hours per day 7 days per week and has 50 bicycles on hand. on average, 10 guests request a bicycle each day, arriving completely randomly at all times of the day during the spring and summer seasons. guests keep bicycles for four days on average, with a standard deviation of two days. how long does a guest on average have to wait for a bike? a. approximately 24 hours b. approximately 0.033 hours c. approximately 4 days d. approximately 47 minutes

Dawn is selling her mp3 player for 3 4 of the original price. the original price for the mp3 player was $40. how much is she selling her mp3 player for?