Aisha just received a $50 paycheck from her new job. She spends some of it buying music online and saves the rest in a bank account. Her savings is given by f(x) = 50-1.30x, where x is the number of songs she downloads.

Question

Aisha just received a $50 paycheck from her new job.  She spends some of it buying music online and saves the rest in a bank account.  Her savings is given by f(x) = 50-1.30x, where x is the number of songs she downloads.

anonymous · Answer

whats the question?

nwolf · Answer

f(x)=50-1.30x

anonymous · Answer

what about it, its an equation are you asking i its the correct equation for the given information?

nwolf · Answer

Find F(18) 
but i am also not sure what they are asking

anonymous · Answer

they are asking find (50-1.30x) when x=18  f(x) gives you 50-1.30x f(18) gives you50-1.30(18)

anonymous · Answer

Yep, the wordy's weird!

nwolf · Answer

Ok now it is asking what does f(18) represent? Would that be the number of songs downloaded. If I did the problem correctly from 50-1.30(18) I got 26.6 does that sound right?

anonymous · Answer

18 does represent the number of songs she purchased, do you understand what the 26.6 represents?

nwolf · Answer

no is that the price per song

anonymous · Answer

@nwolf focus on the question?

anonymous · Answer

"Her savings is given by f(x) = 50-1.30x, ..."

anonymous · Answer

You're working on the f(x), so what is its purpose?

anonymous · Answer

@nwolf Do you follow?

nwolf · Answer

no the F(x) messes me up.

anonymous · Answer

if x=number of songs purchased what would you be figuring out using that equation?
f(x) is just notation its just a number dont let it scare you

nwolf · Answer

so can you tell me what the 26.6 stands for or does that matter?

anonymous · Answer

it represents the amount that she saved

anonymous · Answer

That's why the sentence starts with "Her saving ..."

nwolf · Answer

oh

anonymous · Answer

f(x) is function to find her saving :)

nwolf · Answer

ok just to see if I understand this right, she saves 26.6 but if she wants to buy songs and still save 40$ and she buys 18 songs what is the price per song?  Do I take 40 and divide by 18 and that should give me the price per song??

anonymous · Answer

The price per song is $1.30!

anonymous · Answer

It's a default value, the variable is the number of songs!

nwolf · Answer

oh my!! not I lost myself all over again.. so at 1.30 she can buy 7 songs since she wants to save 40$$ is that right?

anonymous · Answer

Yep, look like you set it straight now :)

anonymous · Answer

If you want us to help you easily, you need to post entirely problem, otherwise we have to guesssing around, then mislead you. That's never our intend!

anonymous · Answer

Is it crystal clear about the purpose of f(x) and what x stands for now?

nwolf · Answer

then can you tell me what is mant by what does f(18)) represent?

anonymous · Answer

f(x) = f(18) 
means x = 18 songs

nwolf · Answer

this part I am kinda lost on.

anonymous · Answer

f(18) = 50 - 1.3 * 18
1.3 * 18 is the cost of 18 songs
=> 50 - (1.3 * 18) is her saving left over after the cost of 18 songs which f(18)

nwolf · Answer

what I am lost on is if 18 the the amount of songs then she can't buy 18 because she only wants to spend 10$

anonymous · Answer

Since you don't post the whole problem, we can't understand where you lost?

anonymous · Answer

On your post, there's no number 18, 10, 40,.. so we don't know where do them come from?

nwolf · Answer

ok let me try again to post it and see 
 Aisha just received a $50 paycheck from her new job.  She spends some of it buying music online and saves the rest in a bank account.  Her savings is given by f(x) = 50-1.30x, where x is the number of songs she downloads.

a. Find f(18).  What does this value (the answer to f(18)) represent?




b. How many songs can Aisha buy if she wants to save $40?

anonymous · Answer

See, that's where we have trouble to help you!

anonymous · Answer

F(18) is the saving left over after purchase 18 songs!

anonymous · Answer

make f(x)=40 so 
40=50-1.30x and solve for x

anonymous · Answer

@Mcronin, thank god you come back, I just don't know head and tail :(

anonymous · Answer

Because f(x) is to calculation for saving, so you set it equal to $40
That's how algebra works, it's sort of backward !

anonymous · Answer

@nwolf questions?

nwolf · Answer

so I ended up getting 7.6 does that sound correct?

anonymous · Answer

Yep, almost 8 songs!

anonymous · Answer

I means 7 songs!

anonymous · Answer

If you can understand throughly on problem, next time you can solve million problems :)

nwolf · Answer

cool thanks so much so 7 songs @ 1.30???

anonymous · Answer

Yep!

nwolf · Answer

wow thank god for math people!!!

anonymous · Answer

Any more problem?

nwolf · Answer

I do have another math (word problem that I am lost on)

anonymous · Answer

SEE, the keywork "Her saving .. f(x)" You totally missed it, because you're so intimidate by the letter f(x) :P

anonymous · Answer

Just post it up, I'm restart my PC in 5 min!

nwolf · Answer

Examine the rise of the price of milk from 1997 to 2008.   The average price of a gallon of whole milk in January 1997 was $2.67, and in January 2008, the average price of a gallon of whole milk was $3.87 according to Consumer Price Index. Use the coordinates (1997, 2.67) and (2008, 3.87) to find the slope, or rate of change, between the two points. Describe and show how you arrived at your answer.  Express your answer as a decimal rounded to the nearest hundredth.  What does this answer mean the real world?

anonymous · Answer

(1997, 2.67), (2008, 3.87)
Slope, rate of change: 
=   (3.87 - 2.67)/(2008 - 1997) = $.109/ year

anonymous · Answer

The cost of 1 gallon milk keep increasing averagely $.11 each year from 1997 to 2008! It means the cost of living raising up yearly!