I’m working on a car loan project in my algebra 2 class, and i don’t know where to start on this question. how do you solve for r?

Precalculus question, image attached.

Finding tbe values of the variables in each kite

The table below lists recommended amounts of food to order for 10 party guests. how much of each food item should nathan and amanda order for a graduation party with 55 guests? use the table to answer. item amount fried chicken 16 pieces lasagna 7 pounds deli meats 1.8 pounds sliced cheese 1 and two fifths pounds bakery buns 1 dozen potato salad 2 pounds