SOLUTION: Can you completely factor out the polynomial 2b^2-8b-3 or is it simply prime?

Algebra.Com
Question 118312: Can you completely factor out the polynomial 2b^2-8b-3 or is it simply prime?
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 2 and -3 respectively.

Now multiply the first coefficient 2 and the last coefficient -3 to get -6. Now what two numbers multiply to -6 and add to the middle coefficient -8? 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 -8? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to -8

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

None of these pairs of factors add to -8. So the expression cannot be factored

This means the polynomial is prime.

RELATED QUESTIONS

Is this polynomial prime, {{{2m^2+11mn+9n^2}}}, or can it be factored out... (answered by jim_thompson5910)
How do you completely factor out 8a^3+27b^3 or is it... (answered by jim_thompson5910)
A) Factor each polynomial completely, given that the binomial following it is a factor of (answered by stanbon)
Factor completely. If it is prime, say so.... (answered by jim_thompson5910)
Factor completely. If a polynomial is prime, state this. a^4b^3 + 2a^3b^2 −... (answered by Fombitz)
Factor completely if it is a prime say so.... (answered by josmiceli)
Can you help me solve the following problem. It is to Factor the polynomial completely. (answered by MathLover1)
Factor completely, or state that the polynomial is prime.... (answered by robertb)
Can you please help me with this problem? 25x^2-4/49 factor out completely or state... (answered by stanbon)