ALGEBRA 2 help please take a look at the screenshot picture and help me solve this question! Thanks!

Question and answers are in the attached picture. you so much in advance.

Arestaurant charges $100 to rent its banquet room for an event. it also charges $15 to serve dinner to each guest. write an equation for the total cost of the banquet room in terms of the number of guests. deine your variables. what is the total cost of the banquet room for 20 guests?

Determine which postulate or theorem can be used to prove that lmn =nmo