13) Mark scored 78, 79, 80, 81, 72, 79, 87, 78, 75, 77 on his first ten tests in Math. What must he make on his 11th test to have an average of 80%?
a)93
b)94
c)95
d)96

True or false look at the picture pls : /

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)) =

Use the elimination method to solve the systems of equations.choose the correct ordered pair. 7x+4y=39