HELP! Does anyone know which answer is correct? I would really appreciate it if someone knows!

The graph represents the gallons of water in a water tank with respect to the number of hours since it was completely filled

Two numbers have a sum of -19. one number is x. what expression represents the other number?

Ineed big ! the cost of a school banquet is $25 plus $15 for each person attending. create a table, sketch the graph, and write an equation in slope-intercept and point-slope form that gives total cost as a function of the number of people attending. what is the cost for 77 people?