SOLUTION: I can't find the answer to the following question on my assignment... I have to use the window or box method to factor this equation... 4x^2-6x+8 If I could get the factors

Algebra.Com
Question 618245: I can't find the answer to the following question on my assignment... I have to use the window or box method to factor this equation...
4x^2-6x+8
If I could get the factors I know how to do the box but I can't get it factored.

Answer by richwmiller(17219)   (Show Source): You can put this solution on YOUR website!
4x^2-6x+8
factor out 2
2x^2-3x+4
Solved by pluggable solver: Factoring using the AC method (Factor by Grouping)


Looking at the expression , we can see that the first coefficient is , the second coefficient is , and the last term is .



Now multiply the first coefficient by the last term to get .



Now the question is: what two whole numbers multiply to (the previous product) and add to the second coefficient ?



To find these two numbers, we need to list all of the factors of (the previous product).



Factors of :

1,2,4,8

-1,-2,-4,-8



Note: list the negative of each factor. This will allow us to find all possible combinations.



These factors pair up and multiply to .

1*8 = 8
2*4 = 8
(-1)*(-8) = 8
(-2)*(-4) = 8


Now let's add up each pair of factors to see if one pair adds to the middle coefficient :



First NumberSecond NumberSum
181+8=9
242+4=6
-1-8-1+(-8)=-9
-2-4-2+(-4)=-6




From the table, we can see that there are no pairs of numbers which add to . So cannot be factored.



===============================================================





Answer:



So doesn't factor at all (over the rational numbers).



So is prime.



RELATED QUESTIONS

Hi I am having great difficulty trying to solve the following:- I have tried puting (answered by amylouise93,jim_thompson5910)
Hello, I am working through my application of derivatives assignment and have come across (answered by rothauserc)
factorize 3a^3b-243ab^3 this is my assignment question but i have no idea how to answer... (answered by orca)
I have a factoring issue. I apologize if my question is in the incorrect category. I... (answered by stanbon)
how do you find the answer for a variable for expansion allowance in highway... (answered by scott8148)
I have have to plot the following, y=100 -6x, I have to find the slope, the y intercept... (answered by checkley71)
I'm not sure if this is the right subject line but I am working with decimal points and... (answered by stanbon)
My homework assignment is to write an indirect proof with the answer 1.5. How can I do... (answered by stanbon)
I need to use synthetic division to factor 3x^3-16x^2-72 into (x-6) and blank? I have no... (answered by stanbon,funmath)