Question

Mila borrowed some money from her friend in order to help buy a new video game system and agreed to pay the friend back a constant amount each week. Mila originally borrowed $100 from her friend and after 3 weeks, she still owed her friend $70. Write an equation for the function L(t), representing the amount Mila owes her friend after t weeks.

Answer 1

Answer:L(t) = 100 - 10t

Explanation:

The total amount of money that Mila borrowed from her friend in order to buy the video game system is $100. Let x represent the constant amount that she agreed to pay each week.

After 3 weeks, she still owed her friend $70. This means that the amount that she paid in 3 weeks is 100 - 70 = $30. Since she pays $x per week, her payment in 3 weeks will be 3×x = $3x. Therefore,

3x = 30

x = 30/3 = 10

She pays $10 each week

Let t represent the number of weeks. The function, L(t), representing the amount Mila owes her friend after t weeks would be

L(t) = 100 - 10t