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View Full Version : Word problem: The J-Mart Corp. is opening new stores....

goingnutz
07-09-2006, 11:47 PM
I need help with the set up of a word problem, I don't want the answer, just some help on setting it up. I'm home schooling my son, and we can't figure out the setup on this problem. He has a hard time with algebra, and I'm at a loss with helping him. I would really appreciate a little help.

The J-Mart Corporation is opening stores in a new territory. The Marketing Division has provided an equation for projected revenue for the next five years for the area, as shown below. The equation is based on a computer prediction using statistics from the area and past experiences.

. . .R = 35y – 17y<sup>2</sup> + 15y<sup>3</sup> – 2y<sup>4</sup>

...where R is the projected revenue of the area in \$1000 and y is the years from the opening of the new territory, from y = 0 to y = 5.

a) What does the equation predict the revenue from the area will be at the end of each of the first five years?

b) What might happen if you were to try to use this equation to predict the revenue for the 7th year?

stapel
07-10-2006, 12:00 AM
a) They ask for the value of R when y = 5, so plug in "5" for "y" and simplify to find the value of "R".

b) What does the graph look like? What sorts of values do you get for R when you use y-values past the end of the intended domain?

Eliz.

goingnutz
07-10-2006, 12:30 AM
There is no graph, what I posted is how it is.
Thanks for the help :)

Denis
07-10-2006, 10:34 AM
R = 35y – 17y2 + 15y3 – 2y4
Next time, show like this:
R = 35y – 17y^2 + 15y^3 – 2y^4
Examples:
R = 1: 35(1) -17(1^2) + 15(1^3) - 2(1^4) = 16 : profit 16,000

R = 5: 35(5) -17(5^2) + 15(5^3) - 2(5^4) = 375 : profit 375,000

R = 7: 35(7) -17(7^2) + 15(7^3) - 2(7^4) = -245 : loss -245,000 :(

Eliz was not telling you there WAS a graph: she was asking you what
do you get IF YOU create a graph.
Graphing would indicate the above results; but you are not familiar (yet)
with graphs, I take it :?:

In case you're not familiar with stuff like y^3: that means y to the power 3:
if y = 5 then y^3 = 5 times 5 times 5 = 125: capish?

goingnutz
07-10-2006, 01:32 PM
Thank you Denis!!!! :D