Can someone help me with a math problem?

[WarDemon666]

this is the question:

Factor:
a^3 - 11a^2 + 5a - 55


Im guessing i would have to use grouping, so (a^3 - 11a^2) + (5a - 55)?


I need help i have to idea how to go about doing this.

This is the only part of the course im having trouble with..

Can you provide the steps to get to the answer? I learn visually..

Thanks a lot,
Carl

 

[Loggerman]

Originally posted by: WarDemon666
this is the question:

Factor:
a^3 - 11a^2 + 5a - 55


Im guessing i would have to use grouping, so (a^3 - 11a^2) + (5a - 55)?


I need help i have to idea how to go about doing this.

This is the only part of the course im having trouble with..

Can you provide the steps to get to the answer? I learn visually..

Thanks a lot,
Carl

Go ask your mommy then

 

[agnitrate]

All of the roots mutiply together to be 55. Some divisor of 55 is a zero of the polynomial. Find one and divide the polynomial by (x-a) where a is that zero and you should get an easier polynomial to work with. Rinse and repeat.

[edit] I just tried 5, no worky, tried 11, worky

-silver

 

[WarDemon666]

Heres what i got:

a^3 - 11a^2 + 5a - 55
a^2(a-11) + 5(a-11)
(a^2 + 5) (a-11)<<------------Final answer


Is this right? I have a feeling i can go further into the equation

Thanks.

 

[WarDemon666]

^^^^

 

[AgaBoogaBoo]

Originally posted by: WarDemon666
Heres what i got:

a^3 - 11a^2 + 5a - 55
a^2(a-11) + 5(a-11)
(a^2 + 5) (a-11)<<------------Final answer


Is this right? I have a feeling i can go further into the equation

Thanks.

correct

 

[WarDemon666]

Sweet deal....

Thanks a lot!

 

[Muzzan]

You /can/ go further and reduce to only linear factors, (a^2 + 5) (a - 11) = (a + sqrt(5)i)(a - sqrt(5)i)(a - 11). Whether or not you /want/ to do that is a different matter altogether 😉