Answer:
B(t) = 1500 - 75(t)
It will take her 20 months to pay off her debt.
Explanation:
Vanessa purchased a smart TV for $1500 on a payment plan. 4 months after purchasing the TV her balance was $1200. This means for the 4 months period she paid $300 . This simply translate to her paying $75 each month for the 4 month duration.
7 months after her balance was $975 . For 7 months duration her balance was $975 which simply means she paid 7 × 75 = $525 during the 7 months period.
The equation to model the balance B(t) after t months can be represented below.
Each month she pays $75 to dislodge her debt. For t months her balance will be
B(t) = 1500 - 75(t)
The number of month it will take her to pay off her loan means her balance will be $0.
B(t) = 1500 - 75(t)
-1500 = -75t
t = -1500/-75
t = 20
It will take her 20 months to pay off her debt.