Which of the following shows 7 + (x + 4y) rewritten using the associative property of addition? select one: a. 7 + x + 4y b. 7x + (4 + y) c. (7 + x) + 4y d. x + (7 + 4y)

Charlie is at an amusement park that has 18 different rides. each ride costs $1.75. the function c(r) = 1.75r represents the total amount of money that charlie will spend if he goes on r rides, but he never goes on the same one more than once. what domain and range are reasonable for the function?