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**deiv****Guest**

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

tnx....

**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,294

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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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 84,225

Hi;

Or take it over to Wolfram.

**In mathematics, you don't understand things. You just get used to them.I have the result, but I do not yet know how to get it.All physicists, and a good many quite respectable mathematicians are contemptuous about proof.**

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**deiv****Guest**

How about this one? What are the factors of:

3x(x+2y) + 4y(3x+2y)

**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,294

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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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 84,225

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.I have the result, but I do not yet know how to get it.All physicists, and a good many quite respectable mathematicians are contemptuous about proof.**

**Online**

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