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This bit of math is really stumping me and i've got math first hour so i dont really have to time to get help from my teacher unless i get there when he does and even then i'll still have some problems left.

here is an example.

8 = 3
4x - 1 x + 3

i'm suppose to set up cross products and that i can do. then i'm to solve for x which is where i get lost. The rest of it says:

8(x + 3) = 4x - 3)(3)
ex + 24 = 12x - 3
27 = 4x
x = 6 3/4

then it goes to check and it says:

(8) (x + 3) = (4x - 1)(3)
(8)(6 3/4 + 3) = (27 - 1)(3)
78 = 78


the answer comes out 78 somehow. can anyone PLEASE explain this to me? I'd be very very very grateful to anyone who can! Thanks!!

Well, as you said, the way to solve the problem is to cross-multiply. Let's start with the 8. I'll try to explain.

First off, multiply the 8 by the x in (x+3), followed by the 3. You should now have (8x+24) on one side of the equation.

For the other side, multiply 4x-1 by the 3 on the other side of the equation. You should now end up with 12x-3. With me so far?

So now, the equation is this: 8x + 24 = 12x - 3

Moving all the unknowns on one side, and the whole numbers on the other, you get

-4x = -27

Solving for x, you get

x = 27/4 (leave it as a improper fraction)

Try to plug in x using 27/4. See if that helps.

THANK YOU SOOOOO VERY VERY VERY VERY VERY MUCH! I think i can get the rest of it done. THANKS AGAIN!!

Any time. Algebra is one thing I'm good at when comes to math. Unless the problems deal with interest, salary rates, or the "how long or how old will this be in x amount time?" crap.

I'm awfully thankfull for your help and i'm now scared of being forced to do such problems. Oh well, i'll take it as it comes and put up a resonable "debate" on why i shouldn't do such problems. Thanks again for the help.

K. Ayato wrote:Any time. Algebra is one thing I'm good at when comes to math. Unless the problems deal with interest, salary rates, or the "how long or how old will this be in x amount time?" crap.

Haha, me too. I was in honors algebra, but when it came to geometry, I was in the regular class. Anything higher than geo? Forget about it ^^. I didn't want to destroy my GPA.

Kiba-kun! Why have you never asked ME for help on your math? I'm only on your messenger service and am taking Calculus II! I feel useless now...*cries*

Doe Johnson wrote:Kiba-kun! Why have you never asked ME for help on your math? I'm only on your messenger service and am taking Calculus II! I feel useless now...*cries*

heres how it works... you take calc... you forget basic math it's inevitable, happened to me in the calc days too

[quote="Lynx"]heres how it works... you take calc... you forget basic math ]
Actually, I'm fairly bad at Calc (an A does not constitute being good). It's this thing called I hate math but I understand it. But I think my understanding is at a basic level, meaning I don't really comprehend what I'm doing now. So anyway, I don't really put effort into learning why I'm doing stuff...or what I'm doing for that matter. It will generally come to me after I've done it for a while. I think the only thing that keeps me sane is using the basic algebra concepts.

Did that make any sense? I usually end up contradicting myself in explaining my love/hate relationship with math. I swear I have to explain it every other day when people realize: "You are a Foreign Language major and you are taking Calc II just for the sake of taking Calc II?!"

Doe Johnson wrote:Kiba-kun! Why have you never asked ME for help on your math? I'm only on your messenger service and am taking Calculus II! I feel useless now...*cries*

I'm sorry. If I realized that you wanted to help with math I would have asked but I felt it was my duty as a friend to make sure you don't stop doing that pointless collage stuff to help this wannabe algebra student.

But if you want next time I'm stuck i'll ask you or a website that i got from my cousin.

Lynx wrote:heres how it works... you take calc... you forget basic math ]

Not necessarily. I'll be taking Diff-Eqs and Linear Algebra in my next semester, but I have maintained a fairly tight grasp on my basic Algebra skills. What's more interesting is that, while I did forget some of the 10th grade Geometry formulas, I relearned them as I was asked to prove them using integral calculus. They make more sense to me that way anyway.

Kiba-Kun wrote:Oh well, i'll take it as it comes and put up a resonable "debate" on why i shouldn't do such problems.

The reason you are forced to do these types of problems is because mathematics is cumulative. You won't be able to survive in college math if you ware wanting in your algebra and pre-calc skills. Trust me, work hard now; the more effort you put into your algebra/pre-calc the easier calculus will be. In reality, a lot of the higher math involves applications of the basics that you learn throughout your school career, with the addition of a lot of concepts.

I am so confused....o.0;

don't worry i'm confused about algebra too.

and i can still put up a "debate" whether it's mandatory to take it or not =P it just means that I can't obey to the will of the government