A school needs to purchase desks and chairs. Each desk costs 12 dollars and it's 8 dollars for each chair. Write an algebraic
expression to find the total cost if the school buys x desks and
y chairs. Write your answer in the form“ ax + by” where a
and b are positive or negative constants.

Mrs. avila is buying a wallpaper border to go on all of her kitchen walls. she wants to buy 5 extra feet of wallpaper border than she needs to be sure she has enough. she buys 55.5 feet of the border. the store owner selling the border uses the width of mrs. avila's kitchen to determine that the length of her kitchen must be 14.5 feet.