Question

A new apartment building was sold for $125000 4 years after it was purchased. The original owners calculated that the building appreciated $3000 per year while they owned it. Find a linear function that describes the appreciation of the building, if x is a number of years since the original purchase.

Answer 1

y = mx + b

y = new price of apartment
m = amount changed per year
x = change in time
b = starting price of apartment

it gives us one scenario, so solve for b:
125,000 = (3000)4 + b
b = 113,000

Therefore, the linear function associated with this is...

y = 3000x + 113000