Simplify the following
a) (5x+4y) (5x-4y)
b) (x -y) (x+xy+yy)

Gerda, a real estate agent, is selling a moderately priced house in a subdivision. she knows from her uncle that the factory being built half a mile from the subdivision will be manufacturing dog food, using a process that creates a very strong odor that permeates the surrounding neighborhood. a buyer, who is unaware of the type of factory under construction, makes an offer on one of the houses gerda is selling, and within a short time, the deal goes through. what does this scenario best illustrate?

Which of the following distribution systems offers speed and reliability when emergency supplies are needed overseas? a. railroadsb. airfreightc. truckingd. pipelinese. waterways

Atennis club charges a monthly membership fee of $150 and charges it members $10 per hour to use a court. there's also $500 fee to become a member. stella joined the tennis club last spring, and she has been a member for 5 months. she has been playing 10 hours of tennis each month. stella values an hour of her time at $20. during a boring afternoon meeting, stella thinks about reserving a court to work on her serve for an hour tonight. what's stella's opportunity cost of working on her serve for an hour?