The organizers of the concert arranged 390 chairs in a row so that there were 18 chairs in the first row and 42 chairs in the last row, and the number of chairs in the rows forms an arithmetic progression. How many chairs were placed in rows, and how many chairs in each subsequent row are more than the previous one?

Give all possible names for the line shown.calculation tip: lines can be written with either point first.

Select all the correct answers. what is 221,000,000,000,000,000,000 expressed in scientific notation?

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)) =