Kohlenwasserstoffe, die keine doppel- oder dreifachbindungen enthalten will report if not right

Ineed to know the answer to this algebra question.

Write two point-slope equations for the line passing through the points (6, 5) and (3, 1)

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.