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So i have the following math problem and im stumped.

A department store's revenue, in millions, can be approximated using the equation R=-0.57y^2+28.88y+115.01, where R represents the revenue each year from 1998 to 2004 and y represents the number of years since 1998, which corresponds to y=0. In what year between 1998 and 2004 did the department store's revenue reach $249 million?

Anyone know the answer? An explanation on how to solve this would also be great.

Is there a parenthesis in there in the begining?

Like
(-0.57y)^2

or (-0.57)(y^2)

If no, then I follow what I remember the order of operations being so Y^2 gets done first and then multiplied with -0.57


Automatically Appended Next Post:
I get 6 years so 2004

You could set it up thusly

249 = -0.57y^2+28.88y+115.01 and then solve for Y

Or

Just pick a number between 0-7 and plug it into the equation and see if it works (which is what I did cause feth solveing for exponents I forget how and I never want to remember!!!!!!)

It says that 1989 would equal year 0

so if y equals a number between 0-7 it coresponds to one of the following years...

1998 = 0
1999 = 1
2000 = 3
2001 = 4
2002 = 5
2003 = 6
2004 = 7

However I may just be one of those peope on the internet who are wrong when it comes to math...

And the actual answer would be?

Because i don't get why you are subbing in Y for those values

Also there are no parenthesis at all.

2004 I think

It says to sub Y for those values

Yeah i read the bit where it says that Y corresponds to the years since 1998...but then it says y = 0.

lol which is what confused the hell out of me .

Seems like you are seeing it as

0 = 1998
1 = 1999
2 = 2000

and so on...so again what does it mean by Y = 0? Because that made my brain freeze when reading the problem.

Some point during 2003. Via graphing calculator.
To solve it properly though, you need to calculate the value Y when R=249, so the equation can become:

249 = (-0.57y^2) + 28.88y + 115.01

You then rearrange it so that you have a simple binomial expansion, by putting all the terms on one side, and making y^2 positive, by moving the entire equation across:

(0.57y^2) - 28.88y + 113.99 = 0

You can also try and simplify it further by making it so that the coefficient of y^2 is 1, rather than 0.57, by dividing each term by 0.57:

y^2 - 50.666y + 200 = 0
(I've rounded slightly so that you don't just copy wholesale)
You then factorise it, into the form
(y - a)(y - b) = 0, with a and b being the two possible answers, though only one of them falls between 1998 and 2004 (the extra year fell somewhere around 2043)

Hope that helps.


Automatically Appended Next Post:

 Akaiyou wrote:
and so on...so again what does it mean by Y = 0? Because that made my brain freeze when reading the problem.

Well, if Y is the number of years since 1998, and in a specific case Y = 0, then there have been no years since 1998, and so the year must be 1998.
Once you calculate Y using the formula, you need to add it to 1998 to calculate the actual year, rather tha just the number of years since 1998.

Thank you very much.

I feel like Tom Sawyer just got us to white wash a fence.

Ahtman wrote:I feel like Tom Sawyer just got us to white wash a fence.

You win the Internets tonight.

 Ahtman wrote:
I feel like Tom Sawyer just got us to white wash a fence.

I didn't give him every part of the answer, so he'll have to do some work himself.
Also I was unable to sleep last night, so the question gave me something to do.
Also also hopefully I explained it well enough that in the future he'llbe able to look at a similar question and do it himself. (I'm not sure whether I actually did, but oh well)

All your lunch-money are belong to me.

 Goliath wrote:

 Ahtman wrote:
I feel like Tom Sawyer just got us to white wash a fence.

I didn't give him every part of the answer, so he'll have to do some work himself.
Also I was unable to sleep last night, so the question gave me something to do.
Also also hopefully I explained it well enough that in the future he'llbe able to look at a similar question and do it himself. (I'm not sure whether I actually did, but oh well)

I don't feel that you used enough 'also's into your post.


Automatically Appended Next Post:

 Albatross wrote:
All your lunch-money are belong to me.

But then I won't be able to get chocolate milk

I also tried to also explain it in a way that he can also know how to do it, and possibly also do this question himself.