Im struggling on this problem i need help if you know (-x+3)-(x-5) PLEASE show THE WORK

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?

For what values of a is the sum of the fractions 2a−1 / 4 and a−1 /3 positive?

Answer for 15 points (look at the image)