SOLUTION: Johann has an antique printing press that he inherited from his grandfather.The printing press is currently worth $26 600, and it has been appreciating at a rate of 3% each year.

Algebra ->  Systems-of-equations -> SOLUTION: Johann has an antique printing press that he inherited from his grandfather.The printing press is currently worth $26 600, and it has been appreciating at a rate of 3% each year.       Log On


   



Question 1037471: Johann has an antique printing press that he inherited from his grandfather.The printing press is currently worth $26 600, and it has been appreciating at a rate of 3% each year. Use a graphical model of the problem to predict how many years will it take for the value of the printing press to double.
Thanks so much :)

Found 2 solutions by Theo, josmiceli:
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
the equation you are looking for is y = 26600 * 1.03^x.

x is the number of years.

the current year is year 0.

the value when x = 0 is 26600 * 1.03^0 = 26600.
the value when x = 1 is 26600 * 1.03^1 = 27398.

you can solve for when it will double by formula as follows:

2 * 26600 = 53200.

formula becomes 53200 = 26600 * 1.03^x.
divide both sides of this equation by 26600 to get 2 = 1.03^x.

2 = 1.03^x is the formula you would use.
take the log of both sides of this equation to get log(2) = log(1.03^x).
log(1.03^x) is equivalent to x * log(1.03)
formula becomes log(2) = x * log(1.03)
divide both sides of the equation by log(1.03) and solve for x to get x = log(2) / log(1.03).
your solution should be x = 23.44977225 years.

graphically, you would graph the function of y = 26600 * 1.03^2.
you would also graph y = 53200.
the intersection of the two equations will be the solution.

the graph looks like this:

$$$

the graph shows that the intersection of the two equation occurs when x = 23.45.

that's the same answer you got by formula after it is rounded to two decimal places.

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
You need to plot some points, +V+, value
on the vertical axis, and +t+ time in years
on the horizontal axis
-----------------------
The equation is:
+V+=+26600%2A%28+1+%2B+r+%29%5Et+
where +r+=+.03+
-------------------
+V%5B0%5D+=+26600%2A1.03%5E0+
+V%5B0%5D+=+26600+
This is the point ( 0, 26600 )
--------------------------
+V%5B1%5D+=+26600%2A1.03%5E1+
+V%5B1%5D+=+27398+
This is the point ( 1, 27398 )
---------------------------
+V%5B2%5D+=+26600%2A1.03%5E2+
+V%5B2%5D+=+26600%2A1.0609+
+V%5B2%5D+=+28219.94+
----------------------------
keep adding points and try to predict the
year, +t+ when +V%5Bt%5D+=+53200+
------------------------------
Here's the actual plot up to about +35+ years
so you can cheat a little:
+graph%28+400%2C+400%2C+-6%2C+35%2C+-6000%2C+65000%2C+26600%2A1.03%5Ex+%29+