SOLUTION: x^2-12x+20 It's asking me to factor this and that is x squared minus 12x plus 20

Algebra.Com
Question 407530: x^2-12x+20
It's asking me to factor this
and that is x squared minus 12x plus 20

Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!

Looking at we can see that the first term is and the last term is where the coefficients are 1 and 20 respectively.

Now multiply the first coefficient 1 and the last coefficient 20 to get 20. Now what two numbers multiply to 20 and add to the middle coefficient -12? Let's list all of the factors of 20:



Factors of 20:
1,2,4,5,10,20

-1,-2,-4,-5,-10,-20 ...List the negative factors as well. This will allow us to find all possible combinations

These factors pair up and multiply to 20
1*20
2*10
4*5
(-1)*(-20)
(-2)*(-10)
(-4)*(-5)

note: remember two negative numbers multiplied together make a positive number


Now which of these pairs add to -12? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to -12

First NumberSecond NumberSum
1201+20=21
2102+10=12
454+5=9
-1-20-1+(-20)=-21
-2-10-2+(-10)=-12
-4-5-4+(-5)=-9



From this list we can see that -2 and -10 add up to -12 and multiply to 20


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


If you need more help, email me at jim_thompson5910@hotmail.com

Also, please consider visiting my website: http://www.freewebs.com/jimthompson5910/home.html and making a donation. Thank you

Jim

RELATED QUESTIONS

Factor x^2 - 12x +20 (answered by MathLover1)
what is the solution of this problem? can you help me to solve this? x+7 divided by 20x... (answered by richard1234)
Hello, I'm Having trouble trying to factor each polynomial completely. The equation is... (answered by ankor@dixie-net.com)
How will you factor x squared minus 12x minus... (answered by jim_thompson5910)
Find vertex of quadratic function. f(x)=x^2 - 12x+6 (x squared minus 12x plus 6)... (answered by Earlsdon)
Hi, I'm being asked to solve for x by completing the square: -2x^2 + 12x - 6 = 0... (answered by scott8148)
I need to solve these quadratic equations using the method that came from India. I am... (answered by solver91311)
x squared plus 12x plus... (answered by checkley71)
ok, I need to find the intercept And the roots of this equation... y=20x^2 - 282(x) +... (answered by stanbon)