Can you please answer this question for me

Hillel is juggling flaming torches to raise money for charity. his initial appearance raises $500\$500 $500 , and he raises $15\$15 $15 for each minute of juggling performance. the amount rr r of money hillel raises is a function of tt t , the length of his performance in minutes. write the function's formula.

Does anyone know how to do geometryme with this problem

You are at a restaurant and owe $56.20 for your meal. you want to leave an 18% tip. approximately how much is your tip?