I need help i don't understand

Is it true or false i’m trying to pass this test so i can leave school

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?

If f(x) = 4x - 3 and g(x) = x + 4, find (f - g) (x)