13.
y - the amount from the sale
x - a number of tickets
y = 5x + 40
Domain: x ∈ {0, 1, 2, 3, 4, 5}
Range = {40, 45, 50, 55, 60, 65}
15.
y - the cost of renting a law firm
x - a number of hour
y = 100x + 300
Domain: x ∈ {1, 2, 3}
Range = {400, 500, 600}
