Which expressions are equivalent to 5x-15

You are making a blueprint of your bedroom and you plan to use a scale factor of 18 . the actual width of your room is 14 feet and the actual length of your room is 16 feet. determine the width and length of your room on the blueprint. on the blueprint, your room will have a width of feet and a length of feet.

How to do this , and can some one explain

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)) =