How do you turn a fraction into a mixed number

Sum is 17 and their difference is 3

Mrs. blake's bill at a restaurant is $42.75. she wants to leave the waiter an 18% tip. how much will she pay in all, including the tip?

Me its important ! marge runs an ice cream parlor. her speciality is triple chocolate sundaes. she can prepare 1 sundae every 2 minutes, and she earns $1.20 for each sundae she makes . if she just makes sundaes for a single shift of at most 4 hours and at least 2 hours , which function relates her earnings to the number of minutes she works?