Who is good at math?

[Magyk]

I need help stat.
Like, for real.
Anyone.
Please?

Xfire me @ 'magyk'

[Roflraptor]

Just post what you need help with.

[Magyk]

Rational Expressions...and lots of them.



There's that for starters.

Oh, and believe me - I know that's probably "easy" and I'm retarded for not knowing how to do it, but I got stuck with the football/wrestling coach as a teacher this semester... you know, the guy who can't teach worth shit, and has "better things to do" than teach his class? That guy.

[Roflraptor]

The answer is C.

2y/(x*y^2) - 3x/(x^2*y^2) = 2y/(x*y^2) - 3/(x*y^2)

= (2y - 3)/(x*y^2)


Just divide the 3x by the x underneath so it becomes 3/(x*y^2), and group the numerators of both fractions as the denominators are now both equal to x times by y^2.

Edit: Removed an error, said x multiplied by x times by y^2... (tired).

[Magyk]

Alright, that makes sense..

For this one I got A

Is that right?

[Roflraptor]

Multiply the 3t^2/5 by 3/3 (as 3/3 is 1, you aren't changing the fraction), so that it becomes 9t^2/15 and the denominators now match.

So now it just becomes a matter of subtraction of the numerators as both the denominators are equal to 15:

(9t^2-4t^2)/15 = 5t^2/15 = t^2/5

Thus the answer is A.

And yea, you're right with the ninja edit.

[Turky]

LCD is 15, so multiplying the first term by 3/3, you have

9t^2/15 - 4t^2/15

Factor out a common term of 1/15 to make things more clear:

(9t^2 - 4t^2) / 15

And then combine like terms in the parentheses to get

5t^2/15 = t^2/5. The answer is A.

ps: fu raptor :<

[Roflraptor]

Hah, he's getting gangbanged with math.

I added you to xfire btw, Magyk. But I feel that you have what you need to make this reasonably easier.

These usually look intimidating but they are almost always fairly easy.

[Magyk]

Alright.. so I did a few more, and I think I have some of this rational expressions stuff under my belt, but this problem is stumping me.



It must be either A or C right? Because the denominator will have Csquared?

Edit: I came out with A after a few trials.. would that be correct?

[Turquoise Dragon]

Sorry, I knew this stuff, then forgot it after my finals when I realized it would not be useful to me later in life.