# Homework Help: Factoring polynomials

1. Aug 30, 2006

### richievuong

Factoring polynomials(2nd problem)

Factor:

36(2x-y)^2 - 25(u-2y)^2

Having trouble where to start...should I expand out?

Last edited: Aug 31, 2006
2. Aug 30, 2006

### KyoPhan

Is that u and u, or is that suppose to be an x

3. Aug 30, 2006

### StatusX

You can start by noticing that that is the difference of two squares.

4. Aug 31, 2006

### richievuong

Yeah its a U, got it figured out now.

I have another one that i'm having trouble with:

(a^2 - ab)^2 -8b^2(a^2 - ab) + 12b^4

I tried factoring the a^2-ab out

= (a^2-ab)[-8b^2 + (a^2-ab)] + 12b^4

Tried a couple methods none really worked out...what should be my next step? Should i factor a^2-ab to a(a-b)?

Last edited: Aug 31, 2006
5. Sep 1, 2006

### StatusX

Do you know how to factor ax^2+bxy+cy^2? Because this expression is in that form.

6. Sep 2, 2006

### Random333

Make

(a^2 - ab)=X
AND
b^2=Y

Therefore, X^2-8xy+12y^2

Then solve and sub back in.