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#1 2012-11-27 22:07:15

deiv
Guest

factoring polynomials

Pls factor completely: (m^9)-(3•m^3)-2
tnx....

#2 2012-11-27 23:41:01

bob bundy
Moderator
Registered: 2010-06-20
Posts: 6,426

Re: factoring polynomials

hi deiv

Welcome to the forum.

You can simplify the problem by making the substitution

Then it becomes

I notice that x = -1 makes this expression zero, so by the factor theorem (x + 1) is a factor.

From there you can easily get the quadratic that goes with this and you'll find the formula will give another two factors.

Then you can go back to the m expression from there.

Bob


You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

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#3 2012-11-28 00:19:05

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 87,238

Re: factoring polynomials

Hi;

Or take it over to Wolfram.


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

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#4 2012-11-28 00:34:45

deiv
Guest

Re: factoring polynomials

How about this one? What are the factors of:
3x(x+2y) + 4y(3x+2y)

#5 2012-11-28 00:55:10

bob bundy
Moderator
Registered: 2010-06-20
Posts: 6,426

Re: factoring polynomials

What do you get if you multiply out the brackets and simplfy?

Bob


You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

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#6 2012-11-28 01:30:59

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 87,238

Re: factoring polynomials

I think you are going to find that is irreducible in Q and therefore in Z.


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

Offline

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