# Thread: Factoring and the Quadratic Formula

1. ## Factoring and the Quadratic Formula

Yeah...kinda forgot i had this over the weekend, and forgot how to do it. Oops. Anyway...
We're supposed to factor if possible, and then solve with the quadratic formula. I think i got the factoring done, but i can't figure the rest out for the life of me.

$\displaystyle -2x+6x+9$

$\displaystyle -4x^2+8x-2$
Factor by two...
-2x^2+4x-1
$\displaystyle -5x^2+5x+5$
Factor by five...
-x^2+x-1
$\displaystyle 2x^2+6x-9$

$\displaystyle x^2+6x-3$

did i do the factoring right? and what do i have to do after?

2. Is this what you're looking for?

3. Ok.. i see now. I just couldn't tell what was a/b/c. Thanks!

Now.. how do you determine the plus-or-minus thing?

And does anyone know a way to memorize the quadratic formula aside from Pop Goes the Weasel? :P

4. Originally Posted by Nightfire
Now.. how do you determine the plus-or-minus thing?
You do 2 seperate equations, one with the plus, the other with the minus.
This should give 2 different values for x.