# How to factor?

• Sep 24th 2011, 08:33 AM
tmac20
How to factor?
How do I factor an equation like this:

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

?
• Sep 24th 2011, 08:36 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 \$\displaystyle 7y^3-2y^2-5y~?\$
If so, let \$\displaystyle y=(x-3).\$
• Sep 24th 2011, 08:52 AM
tmac20
Re: How to factor?
Quote:

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

Thanks, does this sound right:

(x-3)[7(x-3)+5][(x-3)-1]
• Sep 24th 2011, 08:58 AM
Plato
Re: How to factor?
Quote:

Originally Posted by tmac20
Thanks, does this sound right:

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

\$\displaystyle (x-3)[7(x-3)+5][(x-3)-1]=(x-3)(7x-16)(x-4)\$
• Sep 24th 2011, 09:10 AM
tmac20
Re: How to factor?
Quote:

Originally Posted by Plato
\$\displaystyle (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?
• Sep 24th 2011, 09:21 AM
Siron
Re: How to factor?
Consider \$\displaystyle x^2-8x-4y^2-8y+12\$ as a quadratic expression in \$\displaystyle x\$, so use the quadratic formula to factore the expression.