Help me please is for today :((

Which equation represents the function on the graph?

Ebuka's monthly rent is $750. if ebuka pays the rent late, his landlord charges 4% interest per week that the payment is late. write a function that gives the total cost r(t), in dollars, of ebuka's rent if he pays it t weeks late.

What is the effect on the graph of the function f(x) = x2 when f(x) is changed to f(x) − 4?