Question

A 2 year old apartment building was sold for $155000. The owners calculated that the building appreciated $5000 per year while they owned it.
Find a linear function that describes the value of the building over time, if x is a number of years since the original purchase.

Answer 1

If its value grew by $5000/year for 2 years, then it was worth $10,000 more than it cost them. So, 2 years ago, it was worth $145,000. That means the value

v = 145,000 + 5000x

Answer 2

Function: V = Vo + 5000x.
V = Value over time.
Vo = Original value.

155,000 = Vo + 5000*2,
Vo = $145,000.