Pls help me, I don’t understand

On the april 3 billing date, michaelle chappell had a balance due of $ 1495.39 on her credit card. from april 3 through may 2, michaelle charged an additional $ 305.34 and made a payment of $ 800.a) find the finance charge on may 3, using the previous balance method. assume that the interest rate is 1.8 % per month.b) find the new balance on may 3.

Someone answer this asap rn 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)) =

Acomputer store bought a program at a cost of $10 and sold it for $13. find the percent markup