The function, j(x) represents the cost of the Jet ski and B(x) represents the cost of the beach chairs. If j(x) = 30x + 7 and B(x) = 5x + 3
The total cost, C(x) for the rntals at the beach would be the sum of both costs. It becomes
C(x) = 30x + 7 + 5x + 3
Collecting like terms, we have
C(x) = 30x + 5x + 7 + 3
C(x) = 35x + 10
The first option is correct