SOLUTION: In 1940, the cost of a new house was $10,000. By 1980, this cost had risen to $90,000. Assuming that the increase is linear, find a function expressing the cost c of a new house in

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: In 1940, the cost of a new house was $10,000. By 1980, this cost had risen to $90,000. Assuming that the increase is linear, find a function expressing the cost c of a new house in      Log On


   

Question 1106769: In 1940, the cost of a new house was $10,000. By 1980, this cost had risen to $90,000. Assuming that the increase is linear, find a function expressing the cost c of a new house in terms of the year y. Solve this function for y. What does this new function enable you to do?
Answer by rothauserc(4718) About Me  (Show Source):
You can put this solution on YOUR website!
let y be the number of years since 1940
:
slope of line = (90000 - 10000) / (1980 - 1940) = 2000
:
c = 2000y + 10000
:
2000y = (c - 10000)
:
y = (c - 10000) / 2000
:
this new function allows us to predict the years since a house was built based on its cost, then we can add y to 1940 to get the year the house was built
: