Obtenga la diferencia común, el décimo termino y la suma de los primeros 10 términos de cada una de las siguientes series aritméticas: 1) 1,-4,-9...
2) 9/2, 39/8, 21/4,...
3) 125, 95, 65...
4) 1.35, 1.20, 1.05...

Steve wants to develop a way to find the total cost of any item including sales tax. the sales tax in his city is 6%. his friend jenna writes the expression x + 6x where x is the cost of the item. explain whether her expression is correct based on the situation.

In a singing competition, there are 150 participants. at the end of each round, 40% of the participants are eliminated. how many participants are left after n rounds?

Melanie is buying a bathing suit that costs 39.99. she is given a discount at the cash register of $6.00 when she scratched 15% off on a game piece for a store promotion. what will the sale price of melanie’s bathing suit be?