Let a be the sum of the (decimal) digits of 314159. let b be the sum of the digits of a. in this problem, we aim to compute the sum of the digits of b, without the use of a calculator. (a) note that 31 < 102 . use this to give a crude upper bound of the form 314159 < 10n . under this upper bound, what is the most a could be? with this upper bound on a, what is the most b could be? with this upper bound on b, show that b’s digit sum is at most 12.

Which expression gives the area of the triangle shown below

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)) =

3x + 4y = 5 x- 3y = -7 solve by substitution