factoring

• May 24th 2008, 03:33 PM
jscalalamoboy
factoring
Sah...

First off, how do I factor $\displaystyle 8x^2+4x=0$, I also need to factor for x here. Oh, and how do I do fractions in Latex?
• May 24th 2008, 03:41 PM
r_maths
$\displaystyle 8x^{2}+4x=0$

$\displaystyle 4x(2x+1)=0$

$\displaystyle x=0$ , $\displaystyle x=-\frac{1}{2}$

Fraction: $\displaystyle \frac{1}{2}$ (check latex)
• May 24th 2008, 03:41 PM
sean.1986
8x^2 + 4x = 0

4x(2x + 1) = 0
• May 24th 2008, 03:43 PM
dehammer19
firs thing you do is factor out the gcf 4x
then set both factors equal to 0
dose that help?
• May 24th 2008, 03:44 PM
Jonboy
don't you mean you're trying to solve for x?
to factor, just pull out a gcf (greatest common factor) from both terms.

by that, i mean say you have $\displaystyle 9x^2 + 3x = 0$

Both have an x, so you can pull that out. and both are divisible by 3, so pull that out as well.

Now you have: $\displaystyle 3x(3x + 1) = 0$

So solve: $\displaystyle 3x = 0$ and $\displaystyle 3x + 1 = 0$

to make fractions, put \frac{numerator}{denominator}
• May 24th 2008, 04:06 PM
jscalalamoboy
Lol ty all... I completly blanked...
• May 24th 2008, 04:22 PM
jscalalamoboy
NEXT QUESTION! This is why I needed latex for fractions
$\displaystyle \frac{x^2+x-6}{x^2-x-2}$ * $\displaystyle \frac{x^2+5x+4}{x^2+2x-3}$
• May 24th 2008, 04:26 PM
Jonboy
factor everything that you can to try to cross cancel.
remember, you can only do that on multiplication and division.