Can anyone help me figure these questions out?
I need to find what the letters equal

Leslie started last week with $1200 in her checking account. during the week, she wrote the checks below.

Which best explains why this triangle is or is not a right triangle ?

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?