7. A company sells an average of 50 skateboards per month at a price of $120 each. For each $5 decrease in price, two more skateboards are sold. Determine the marginal revenue when 25 skateboards are sold. 8. A beverage stand sells 500 smoozhies per week at a price of $1.20 each. For every $0.10 decrease in price, the number sold per week increases by 20. The cost of smoothies is given by C(x) : 25 +0.12! +0.001x2. Deierminc the marginal prot when 200 smoothies are sold