Let p (n) be the statement that a postage of n cents can be formed using just 4-cent stamps and 7-cent stamps. the parts of this exercise outline a strong induction proof that p(n) is true for n 18.
a) show statements p (18), h19), h20), and f(21) are true, completing the basis step of the proof.
b) what is the inductive hypothesis of the proof?
c) what do you need to prove in the inductive step?
d) complete the inductive step for k 21.
e) explain why these steps show that this statement is true whenever n 18.

Someone answer asap for ! a discount store’s prices are 25% lower than department store prices. the function c(x) = 0.75x can be used to determine the cost c, in dollars, of an item, where x is the department store price, in dollars. if the item has not sold in one month, the discount store takes an additional 20% off the discounted price and an additional $5 off the total purchase. the function d(y) = 0.80y - 5 can be used to find d, the cost, in dollars, of an item that has not been sold for a month, where y is the discount store price, in dollars. create a function d(c(x)) that represents the final price of an item when a costumer buys an item that has been in the discount store for a month. d(c(x)) =