I'm stuck!
ok

part a: marina rented a coat at $285 for 3 days. if as rents the same coat for 6 days she has do pay a total rent of $510

write an equation in the standard form to represent the total rent (y) that marina has to pay for renting the coat for x days.

part b: write the equation obtained in part a using function notation

part c: describe the steps to graph the equation obtained above on the coordinate axes. mention the labels on the axes and the intervals

if i had a done i could do b but i am stuck on a and c

I can do A, I think.
Part A: Marina rented a coat at $285 for 3 days. If as rents the same coat for 6 days she has do pay a total rent of $510. Write an equation in the standard form to represent the total rent (y) that Marina has to pay for renting the coat for x days.
First, find out the base price. If it was $285 for 3 days, then it's: 285/3, which equals $95 per day to rent the coat. Now you can just write the equation. Use the letters x and y to represent the data they want in the equation. 
y (total rent) = 95x (x being the number of days). So your equation will be y = 95x, and if someone wanted to solve it they'd just need to give the value of "x"

Bis the answer! hope this