Algebra help!

[hero_bash]

Can anyone help me simplifying these Ration algebraic expressions?

Thanks in advance!

[emiiru]

ha!! You're in school!!

[Grandy]

By - By
       Y-X

 That should be either zero or impossibe, as By-By is zero.

 That's all I can help now, as it's 2 am here and my father is telling me to go sleep.

 EDIT: And fastly:
  The last-but-one equals 1

 The last one: X is either 0.666... (infinite) or -2

 

[Razor]

We're a math forum now? WHEN DID YOU DO THIS, ALEX?

[SaiKar]

Not going to do all your work for you, but here's how you solve the second one: multiplying things by -1*-1 makes them a bit easier.

The problem is 2-x / x^2-4

Start with the 2-x on top. Multiply it by -1*-1 (which equals 1 so you can do this) and you get -1*(x-2) on the top. One of the -1s changes the signs on both of them so you get -2+x, which is x-2. The other -1 stays outside.

Take the bottom and factor to get (x-2)(x+2). By using FOIL as a check you can prove this does equal x^2-4 since x*x=x^2, x*2=2x, x*-2=-2x and -2*2=4. 2x and -2x cancel so you are left with x^2-4. So that's a correct factorization. Leave it liike (x-2)(x+2)

So now you have -1(x-2) / (x-2)(x+2). Just cancel like terms to get the simplied form of -1 / x + 2.

That's how you solve most of them. If that didn't make much sense than you probably didn't really know how to do these simplification things in the first place.

[Midnight9795]

*stares at Harvey's response for a good while*  :unsure:

[Archem]

Bah! My brain stopped processing algebra a month and a half ago!
Which is prob'ly the reason why i failed algebra 2... :cry:

[Desimodontidae]

Ahh... I was studying this when school ended... had a little trouble, buts easy once you get it down.

[GaryCXJk]

The first one:

( mx - 2nx + my - 2ny ) / ( m^2 - 4n^2 )

The top part can be simplified as:

( m - 2n ) ( x + y )

So, you first get:

( m - 2n ) ( x + y ) / ( m^2 - 4n^2 )

Screw it. That's the simplest I can get at 4 AM.

The second last one is simple:

x^2 - 7x + 12 = 12 - 7x + x^2

Even better, it's the same as:

-7x + 12 + x^2

So, finally, it comes down to 1, because:

x / x = 1

The last one:

( 3x^2 + 4x - 4 ) / ( 4 - 9x^2 )

The first can be broken apart, but that will be hard, but with some tryings, you'll come up with this:

( 3x - 2 ) ( x + 2 )

Now for the second one:

( 2 + 3x ) ( 2 - 3x )

To rule some things out:

( 3x - 2 ) / ( 2 - 3x ) = -1

Also:

-1 * ( x + 2 ) = -x - 2

And to combine:

( -x - 2 ) / ( 2 + 3x )

[Bluhman]

GAH. I can WRITE awnsers to math problems, but not type them. I'm an idiot.  

[DragonBlaze]

Heres a tip, look in your math book and learn how to do it yourself...

[FFL2and3rocks]

*reads thread*

 
*head asplodes*

[DragonBlaze]

I was bored, so I did them all.. Here are the answers from top to bottom.

(see attachement)