Math Help!!!
 

Ok, helping my kid with Honors Algebra 2. I must be fucking brain dead or something because a word problem is driving me nuts!! I can figure out the answer, but not the equation.

In an evening, a sporting goods store sold twice as many T-shirts as shorts. T-shirts are $9 each and shorts are $14 each. The total amount of money taken in for both items was $256. Find the number of each that was sold.

God I feel like an idiot. Never been stumped by a damn word problem before. Any help is mucho appreciated. :Oh crap

16 shirts and 8 shorts

When in doubt - drop back 10 yards - PUNT!

I already know the answer. She has to have the algebraic equation. Thanks though.

(2 * 9y) + 14x = 256

?

9x +14y = 256
2x=y

Solve together....



Oh yeah, hi GFY :2 cents:

This was the first thing I came up with, but doesn't seem right. I couldn't come up with a way to work it.

9x+14y=256

9 x 16= 144
14 x 8= 112

112+114=256

Wow that'll take you back 20 years.

Yep...it definitely did that.

I know that much. Have to show how I came up with the 16 and the 8:winkwink:

assume # of T-shirts sold as T and # of shorts sold as S

T=2S
9T+14S=256
plug in T=2S

9(2S)+14S=256
18S+14S=256
32S=256
S=8
T=2S=16

I also came up with this. I was just wondering if I was missing something. Seems like there should be a single equation way to do it????

no this is the way to solve an eqaution with two unknown

I was never very good at "showing my work". I do those steps unconsciously. It drove my teachers mad.

Why show your work if you can do it in your head?

Ok...been a LONG time for me so I will take your word on this one.

Thanks for the help everyone.:thumbsup

you should do a search online for tutors... they have some that will help your child online.. not only will they help them figure it out, but they will show them how to come up with the answer...

"lead a child to water, but dont drink for them"....

OK, here's how you do it:

Look at the problem. You know that the shop sold T-Shirts and Shorts. You get that just by looking at the words.

But you don't know how many were sold. So they are variables. Call them T (for the number of T-Shirts sold) and S (for the number of shorts sold).

T-Shirts cost $9 so the total money taken in from T-Shirt sales is $9 x T.

Shorts cost $14 so the total amount of money taken in from Shorts sales is $14 x S.

The total money taken in was $256, and this has to equal the total taken in T-Shirts plus the total taken in Shorts, so we have:

($9 x T) + ($14 x S) = $256

Now this has two unknowns so we can't solve it just yet. Instead, we need to look at the word problem for additional information... And there it is: That the store sold twice as many T-Shirts as Shorts. In equations, this is:

T = 2 x S

Now there are two equations in two unknowns, so you just solve. You can plug the value for T from the second equation into the spot where T is in the first:

($9 x 2 x S) + ($14 x S) = $256

simplify:

($9 x 2 + $14) x S = $256

S = $256 / ($9 x 2 + $14)

= $256 / ($18 + $14)

= $256 / $32

= 8

So the number of shorts sold was 8.

Now we can use the second equation to get the value for T.

T = 2 x S

= 2 x 8

= 16

So the number of T-shirts sold was 16.

Let x = amount of shirts
Let y = amount of shorts

2y =x

9x+14y = 256

9(2y)+14y=256
18y+14y=256
32y= 256
y=8
therfore x = 16

There you go.

She is in 10th grade...mostly honors classes...volleyball, basketball, track, and softball teams...NEVER made a B in her life. We were just stumped with this problem for some reason. Thank you though.:winkwink:

Thank you evulvmedia and Alex. That is kinda what I thought, but since it's been so long, wasn't sure if I was missing a way to do it with a single equation.

Thanks again.

I actually enjoyed trying to figure it out. She hasn't needed help in a loooong time. Only her 2nd day in Algebra 2 so she doesn't have it all the way down yet. I helped with most, but that one made my brain hurt.:)

i wasnt trying to belittle your kid or your parenting skills... i was simple saying that there are online sources that might be more useful and have more benefit for your child than just getting the answer on a forum...

That's cool...I'm just saying with straight A's all her life, she doesn't really need tutoring. Just had an issue with 1 problem on the 2nd day of class. Getting this 1 answer on a forum isn't gonna ruin her education. It taught us (reminded me) how to work similar problems in the future.

marketsmart - I will say that I agree with you 10000% though...I know what you mean. I don't DO the work for my kids. I help them to understand better, but they have to know what they are doing. It will do them NO good if I just do everything for them. Trust me though, she does most things on her own, and works her ass off for her grades.:thumbsup

I just got out of high school years back.
So its still fresh.

Trust me at 40+ (or however young you are now :winkwink: ) you tend not to care about this shit and therefore you forget.

Exactly why I came here...plenty of youngin's:winkwink:

The thing is, I had NO problem coming up with the answer. Damn teachers and the whole "show your work" thing killed me. Couldn't remember to save my life...lol.

Nope, 2 variables = 2 equations
3 variables = 3 equations, etc.

Next time can we only go back 10 years instead? :winkwink:

works for me:thumbsup