# How to factor?

• September 24th 2011, 09:33 AM
tmac20
How to factor?
How do I factor an equation like this:

7(x-3)^3 -2(x-3)^2 -5(x-3)

?
• September 24th 2011, 09:36 AM
Plato
Re: How to factor?
Quote:

Originally Posted by tmac20
How do I factor an equation like this:
7(x-3)^3 -2(x-3)^2 -5(x-3)

Can you factor $7y^3-2y^2-5y~?$
If so, let $y=(x-3).$
• September 24th 2011, 09:52 AM
tmac20
Re: How to factor?
Quote:

Originally Posted by Plato
Can you factor $7y^3-2y^2-5y~?$
If so, let $y=(x-3).$

Thanks, does this sound right:

(x-3)[7(x-3)+5][(x-3)-1]
• September 24th 2011, 09:58 AM
Plato
Re: How to factor?
Quote:

Originally Posted by tmac20
Thanks, does this sound right:

$(x-3)[7(x-3)+5][(x-3)-1]$

$(x-3)[7(x-3)+5][(x-3)-1]=(x-3)(7x-16)(x-4)$
• September 24th 2011, 10:10 AM
tmac20
Re: How to factor?
Quote:

Originally Posted by Plato
$(x-3)[7(x-3)+5][(x-3)-1]=(x-3)(7x-16)(x-4)$

Thanks, can you help with with one more problem:
Factor:
x^2 -8x-4y^2 +12-8y

I've gotten this far:
(x-6)(x-2) -4y(y+2)

Can I factor even more from there?
• September 24th 2011, 10:21 AM
Siron
Re: How to factor?
Consider $x^2-8x-4y^2-8y+12$ as a quadratic expression in $x$, so use the quadratic formula to factore the expression.