# Thread: Desperate for math help... Factoring

1. ## Desperate for math help... Factoring

I'm really frustrated because I've been stuck with factoring for the past month and it's been lowering my grade and it's hard to understand my teacher

She has some other way of doing it but I looked aroudn and I guess the box way is easier?? I don't know...

This is as far as I got with ensured correctness. I don't really know what to do... Help is appreciated.

2. Originally Posted by isuckatmath
I'm really frustrated because I've been stuck with factoring for the past month and it's been lowering my grade and it's hard to understand my teacher

She has some other way of doing it but I looked aroudn and I guess the box way is easier?? I don't know...

This is as far as I got with ensured correctness. I don't really know what to do... Help is appreciated.

sorry. not familiar with the box method. here's another way to do it.

multiply the first term by the lone constant, we get 3x^2*(-18) = -54 x^2

now take the middle term. we have -25x

so now we want two terms that when we multiply, we get -54x^2 and when we add we get -25x

thinking a bit ....aha! 2 and -27. since 2 + (-27) = -25 and 2*(-27) = -54

so now we split the middle term into those two numbers. so we go from

3x^2 - 25x - 18

to

3x^2 - 27x + 2x - 18

now we factor by groups. there is a common 3x among the first two terms, and a common 2 among the last two, so pull those out. we get:

3x(x - 9) + 2(x - 9)

now we have a common (x - 9) to both terms, so pull those out. we get

(x - 9)(3x + 2)

So, 3x^2 - 25x - 18 = (x - 9)(3x + 2)

This is one of the standard ways to do this kind of problem, you always follow these steps exactly. if you prefer the boxed method. post a full solution of a problem you worked out using it, and i'll figure it out and explain it to you

3. Thanks