Charas-Project
Off-Topic => All of all! => Topic started by: hero_bash on June 11, 2006, 02:28:25 AM
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Can anyone help me simplifying these Ration algebraic expressions?
Thanks in advance!




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ha!! You're in school!!
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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
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We're a math forum now? WHEN DID YOU DO THIS, ALEX?
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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.
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*stares at Harvey's response for a good while* :unsure:
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Bah! My brain stopped processing algebra a month and a half ago!
Which is prob'ly the reason why i failed algebra 2... :cry:
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Ahh... I was studying this when school ended... had a little trouble, buts easy once you get it down.
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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 )
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GAH. I can WRITE awnsers to math problems, but not type them. I'm an idiot. :x
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Heres a tip, look in your math book and learn how to do it yourself...
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*reads thread*
*head asplodes*
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I was bored, so I did them all.. Here are the answers from top to bottom.
(see attachement)