Factorising

[Guest]

A big hello to whoever can help,
Ok so I have a huge grading test that goes towards my school certificate on friday but I'm having trouble with almost all the questions that at my level I'm supposed to be able to do! and I can't its really frustating me and to make matters worse my dad who is actually really good at factoring is in the Cook Islands so he can't help me so I'm really struggling.
This is the question
Factorise:
x^2y^2z^2-x^2y^2z+x^2y^2z^2

Thank you so much if you can help.
Yours,
Alicia

 

[Gene]

x^2y^2z*z-x^2y^2z*1+x^2y^2z*z

 

[Denis]

x^2y^2z^2-x^2y^2z+x^2y^2z^2

well, I'd start by making your expression clearer (spacing):

x^2 y^2 z^2 - x^2 y^2 z + x^2 y^2 z^2

Now easier to see that (x^2 y^2 z) is common to all 3 terms; so:

x^2 y^2 z(z - 1 + z)

Finish it...