SOLUTION: Hi, I am having trouble with a problem I hope some one can help me please. Factor Completety: 3x - 3x^2 + 6x - 18 I would like to thank you for your help.

Algebra.Com
Question 139640: Hi, I am having trouble with a problem I hope some one can help me please.
Factor Completety:
3x - 3x^2 + 6x - 18
I would like to thank you for your help.

Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!
Are you sure it's not supposed to read: ???

Start with the given expression


Combine like terms



Factor out the GCF


Now let's focus on the inner expression




------------------------------------------------------------



Looking at we can see that the first term is and the last term is where the coefficients are 1 and -6 respectively.

Now multiply the first coefficient 1 and the last coefficient -6 to get -6. Now what two numbers multiply to -6 and add to the middle coefficient 1? Let's list all of the factors of -6:



Factors of -6:
1,2,3,6

-1,-2,-3,-6 ...List the negative factors as well. This will allow us to find all possible combinations

These factors pair up and multiply to -6
(1)*(-6)
(2)*(-3)
(-1)*(6)
(-2)*(3)

note: remember, the product of a negative and a positive number is a negative number


Now which of these pairs add to 1? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to 1

First NumberSecond NumberSum
1-61+(-6)=-5
2-32+(-3)=-1
-16-1+6=5
-23-2+3=1



From this list we can see that -2 and 3 add up to 1 and multiply to -6


Now looking at the expression , replace with (notice adds up to . So it is equivalent to )




Now let's factor by grouping:


Group like terms


Factor out the GCF of out of the first group. Factor out the GCF of out of the second group


Since we have a common term of , we can combine like terms

So factors to


So this also means that factors to (since is equivalent to )



------------------------------------------------------------




So our expression goes from and factors further to


------------------
Answer:

So factors to




RELATED QUESTIONS

Hi, I am having trouble with a problem on my homework, I hope some one can help me,The... (answered by frostusna,checkley75)
I am having a little trouble solving this problem. Could some one please help me so that... (answered by jim_thompson5910)
Hi I'm having some trouble with this problem, we have to divide this algebraic... (answered by stanbon)
Can someone please help me with the work for this problem: 6x^2-11x-10 I need to factor... (answered by checkley71)
hi my name is brittny and i am having trouble with this one problem directions: solve... (answered by wuwei96815)
I am having trouble with this problem. Can you help me please? Factor by grouping... (answered by jim_thompson5910,checkley71)
hi, can you please help me on solving systems using substation this is a problem I am... (answered by amarjeeth123)
Hi, I have been having some trouble with my algebra home work and I am a little behind. I (answered by ankor@dixie-net.com)
Hi i am having trouble with this problem the directions say "change each exponential... (answered by stanbon)