I need help with this question please explain

43lbs of tomatos cost $387. how much would 41lbs cost

Complete the solution of the equation. find the value of y when x equals to 6 4x+y=20

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?