Please solve it for me and show me the correct and right method to solving these kind of questions.

(xcubed + 2xsquared - 5x - 6)

and Thanks alot

2. ## Re :

Originally Posted by itsMoeyy

Please solve it for me and show me the correct and right method to solving these kind of questions.

(xcubed + 2xsquared - 5x - 6)

and Thanks alot

$\displaystyle P(x)=x^3+2x^2-5x-6$

Well , are you familiar with the factor theorem ?
If not , note that for a polynomial P(x),(x-a) is a factor of P(x) if and only if P(a)=0 .

Notice that the constant term for the equation above is -6 .
Hence if (x-a) were to be a factor of P(x) , then a must be a factor of -6.
a=+/-1,+/-2,+/-3,+/-6

Substitute :

If x=1 , P(1)=1+2-5-6=-8 , hence (x-1) is NOT a factor .

If x=-1,P(-1)=-1+2+5-6=0 , hence (x+1) IS a factor .

Try doing this for all values of a stated above and you should get all the factors for this equation .

3. Wow..

But I have no idea how to do it..

Could you explain it a bit more?

and could you also solve the question?

Im kind of dumb so yeahh.. =/

4. Originally Posted by itsMoeyy

Please solve it for me and show me the correct and right method to solving these kind of questions.

(xcubed + 2xsquared - 5x - 6)

and Thanks alot
$\displaystyle 1 ------x^3+2x^2-5x-6)$
$\displaystyle 2-----x^3+x^2+x^2+x-6x-6$
$\displaystyle 3------x^2*(x+1)+x*(x+1)-6*(x+1)$
$\displaystyle 4------(x^2+x-6)*(x+1)$
$\displaystyle 5------(x^2+3x-2x-6)*(x+1)$
$\displaystyle 6------(x*(x+3)-2*(x+3))*(x+1)$
$\displaystyle 7------(x-2)*(x+3)*(x+1)$

5. HOLY MOLEY!

Niceee

How did ya do that? o.O

6. Originally Posted by itsMoeyy
Wow..

But I have no idea how to do it..

Could you explain it a bit more?

and could you also solve the question?

Im kind of dumb so yeahh.. =/

Erm , i have probably explained everything or perhaps i am missing something ..

but i think it is better if you post your working ( substitute all the a's like what i did ) or i do not know where else i can explain

7. I have edited my post tell the step where you didn't get it
Note: * stands for multiplication