SOLUTION: Is this the right factoring x^2-5x-6 (x-2)(x-3)

Algebra.Com
Question 119714: Is this the right factoring
x^2-5x-6
(x-2)(x-3)

Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!
No it is not. If you foil you'll get




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 -5? 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 -5? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to -5

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 1 and -6 add up to -5 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 )



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



Answer:
So factors to

RELATED QUESTIONS

Need help with factoring x^2-36 i got (x+6)(x-6) Is this... (answered by Alan3354)
x^+5x+2... (answered by Alan3354)
3. How do I solve this equation using factoring? Thank you. x^2 + 6 =... (answered by Alan3354)
I have three problems that are factoring Factoring - Finding GCF Reverse... (answered by richwmiller)
I have to use the FOIL to find the product. Express the product as descending powers of... (answered by Theo)
I think I did this one right solve by factoring 5x^2-19x+18=0 5x^2-10x-9x+18=0... (answered by rapaljer)
Factoring completely: 20x^2+100x+40 I have this so far: 20(x^2+5x+2) Is this... (answered by longjonsilver)
fractions x/2-x/3=5 15x-10x=150 5x=150 x=30 is this the right... (answered by Alan3354)
-2x(x+3)-(x+1)(x-2)= -2x^2-5x-x+1 --2x^2+6x+1 is this... (answered by rothauserc)