Nora is a songwriter who collects royalties on her songs whenever they are played in a commercial or a movie. nora will earn $40 every time one of her songs is played in a commercial and she will earn $120 every time one of her songs is played in a movie. nora earned a total of $640 in royalties on 12 commercials and movies. write a system of equations that could be used to determine the number of commercials and the number of movies on which nora's songs were played. define the variables that you use to write the system.

Astudy was interested in determining if eating milk chocolate lowered someone's cholesterol levels.ten people's cholesterol was measured. then, each of these individuals were told to eat 100g of milk chocolate every day and to eat as they normally did. after two weeks, their cholesterol levels were measured again. is there evidence to support that their cholesterol levels went down? how should we write the alternative hypothesis? (mud = the population mean difference= before - after)a. ha: mud = 0b. ha: mud > 0c. ha: mud < 0d. ha: mud does not equal 0

Kevin's bank offered him a 4.5% interest rate for his mortgage. if he purchases 3 points, what will be his new rate?

At store a, erasers are sold individually. the cost y of x erasers is represented by the equation y=0.75x. the costs of erasers at store b are shown in the graph.