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7-90.

Ida wants to buy a car, but she currently does not have any money. The car she wants costs . Consider her two options and decide which loan she should take.  Homework Help ✎

  1. She could borrow at a monthly interest rate of simple interest and pay the total after months. Write a simple-interest expression and calculate what she would owe at the end of months. 

    Use the equation for simple interest from the Math Notes box in this lesson.
    where:



    dollars per month in interest
    interest over months

    How much total money does Ida owe under this option if her borrowed amount is and her interest would be ?

  2. She could borrow at a weekly interest rate of simple interest and pay the total after months. Show calculations and a written explanation to justify your answer.

    Use the same interest formula from part (a).

    There are weeks in a year.

    Ida owes with this option. Be sure to show how to get this answer and explain which one of the two loan options is better and why.