Question

Ariana borrowed some money from her friend in order to help buy a new video game

system. Ariana originally borrowed $150 and agreed to pay back her friend $15 per
week. Write an equation for L, in terms of t, representing the amount Ariana owes
her friend after t weeks.

Answer 1

L = 150 - 15t

Explanation:

Money borrowed by Ariana = $150

Money she returns each week = $15

Amount of borrowed money will decrease by $15 each week.

In 1 week she will return $15

in 2 week she will return $15*2 = $30

in 3 week she will return $15*3 = $45

...........................

similarly after t week

money she will return = Money she returns in 1 week* no of weeks

money she will return in t weeks = 15*t = 15t

where 15t unit is dollar

So, Amount of borrowed money will decrease by $15t in t week.

Amount of money she woes after t week = Money borrowed by Ariana - money returned in t weeks

Amount of money she woes after t week = 150 - 15t

Since L represents the amount Ariana owes ,her friend after t weeks

L = 150 - 15t is the correct answer