Please I need to know how to factorise this quadratic expression!

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

(xcubed + 2xsquared - 5x - 6)

Please help

and Thanks alot :)

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- February 7th 2009, 04:03 AMitsMoeyyFactorising - Please Help!
Please I need to know how to factorise this quadratic expression!

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

(xcubed + 2xsquared - 5x - 6)

Please help

and Thanks alot :) - February 7th 2009, 04:17 AMmathaddictRe :

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 . - February 7th 2009, 04:51 AMitsMoeyy
Wow..

Thanks alot.. Your a genius! :D

But I have no idea how to do it..

Could you explain it a bit more?

and could you also solve the question? (Worried)

Im kind of dumb so yeahh.. =/ - February 7th 2009, 05:04 AMADARSH
- February 7th 2009, 05:06 AMitsMoeyy
HOLY MOLEY!

Niceee

How did ya do that? o.O - February 7th 2009, 05:07 AMmathaddict
- February 7th 2009, 06:04 AMADARSH
I have edited my post tell the step where you didn't get it

Note: * stands for multiplication