Math Is Fun Forum

deiv

Guest

factoring polynomials

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

Bob

Administrator

Registered: 2010-06-20

Posts: 10,646

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

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: factoring polynomials

Hi;

Or take it over to Wolfram.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

deiv

Guest

Re: factoring polynomials

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

Bob

Administrator

Registered: 2010-06-20

Posts: 10,646

Re: factoring polynomials

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

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

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.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.