1. ## basic help?

it's been a while since I've done math, and i know most of this stuff but have some particular rust issues
such as:

in problems such as this one:

(x^2-3x-4) - (x^3+x^2+x+5)

what do I do? Obviously is not multiplying because of that - sign. do I have to solve the first one, which can be done easily, and then just substact the whole thing??

also in another problem I ended up with this:

9x^2-24x+16
I know I can contnue factoring but how exactly do I do it?
(3x- ) (3x+ )

Im not sure what to do when the x^2 has a number in front. do those 3 have to multiply the numbers I use in the blank space??

and this problem tells me to find the quotient and remainder
problem is: 4x^3-3x^3+x+1 divided by x+2

so my question is, how do I even start with this? do I literally divide it or does the x+2 flip to the top and I just multiply the rest??

2. ## Re: basic help?

Originally Posted by purplelove707

(x^2-3x-4) - (x^3+x^2+x+5)

what do I do? Obviously is not multiplying because of that - sign. do I have to solve the first one, which can be done easily, and then just substact the whole thing??

$\displaystyle (x^2-3x-4) - (x^3+x^2+x+5)$

Distribute the minus sign through the second set of brackets

$\displaystyle x^2-3x-4 - x^3-x^2-x-5$

Now group the like terms.

Originally Posted by purplelove707

also in another problem I ended up with this:

9x^2-24x+16
I know I can contnue factoring but how exactly do I do it?
(3x- ) (3x+ )
$\displaystyle (3x- a) (3x+ b)$

find $\displaystyle a$ and $\displaystyle b$ such that $\displaystyle ab=16$ and $\displaystyle 3xb-3xa = -24x$

Originally Posted by purplelove707

and this problem tells me to find the quotient and remainder
problem is: 4x^3-3x^3+x+1 divided by x+2

Read this guy... Polynomial Long Division

3. ## Re: basic help?

Originally Posted by pickslides
$\displaystyle (x^2-3x-4) - (x^3+x^2+x+5)$

Distribute the minus sign through the second set of brackets

$\displaystyle x^2-3x-4 - x^3-x^2-x-5$

Now group the like terms.
thanks

I thought it was something like that, but it seemed too simple. Now I'm just having some issues with some weird answers I'm getting in similar problems, but I can take it from here

gonna read on the polynomial long division. thanks again!

4. ## Re: basic help?

if you can help me with just another thing

there are several problems where I end up with things like this:

x^3+3x^2+3x+1

now I see I can continue factoring by x, but that 1 at the end confuses me. can I just leave it outside of the factoring or does the 1 simply dissapear? or is this the end of the operation?

5. ## Re: basic help?

Originally Posted by purplelove707
if you can help me with just another thing

there are several problems where I end up with things like this:

x^3+3x^2+3x+1

now I see I can continue factoring by x, but that 1 at the end confuses me. can I just leave it outside of the factoring or does the 1 simply dissapear? or is this the end of the operation?
$\displaystyle x^3+3x^2+3x+1$ can be factorised further

Try dividing $\displaystyle x+1$ into $\displaystyle x^3 + 3x^2 + 3x +1$ using the polynomial division you read up on earlier.

Not sure if you have ever seen Pascal's triangle or done binomial coefficients but they can help you factorise equations of this form. Pascal's triangle