# Thread: Factoring Complex Trinomial Quadratics

1. ## Factoring Complex Trinomial Quadratics

- 20x²-24x+32
GCF: 4
4(-5x²-6x+8)

4(-5x-10)(-5x+4) / 4

Product of AC= -40
Sum of B= -6

Please help i cant divide -5x by 4, even if i split 4 to 2x2

2. Originally Posted by buck
- 20x²-24x+32
GCF: 4
4(-5x²-6x+8)

4(-5x-10)(-5x+4) / 4

Product of AC= -40
Sum of B= -6

Please help i cant divide -5x by 4, even if i split 4 to 2x2
where is /4 coming from?? how can you just divide by 4 like that?!

factor out -4, you get $\displaystyle \displaystyle -4(5x^2 + 6x - 8)$

you're using the ac method, so i will as well. here ac = -40 and b = 6, so think of two number that when you multiply them you get -40, but you add them and get 6. 10 and -4 works. so split the middle term into those two, you have:

$\displaystyle \displaystyle -4(5x^2 + 10x - 4x - 8)$

now factor what's inside the brackets using "factor by grouping"

3. wait can i divide it by -20 because my teacher told me you are supposed to divide it by A