SOLUTION: I am trying to figure out if the denominator of this fraction factors any lower than what it is. The fraction is 3x^3+x^2-27x-9/ 2x^3+9x^2-8x-15. I know that I can't factor by grou

Algebra.Com
Question 378418: I am trying to figure out if the denominator of this fraction factors any lower than what it is. The fraction is 3x^3+x^2-27x-9/ 2x^3+9x^2-8x-15. I know that I can't factor by grouping because the groups in this polynomial in the denominator wouldn't have anything in common. I am stuck on this problem and don't know what else to try, please help!!
Answer by solver91311(24713)   (Show Source): You can put this solution on YOUR website!


First use the Rational Roots Theorem which says that if



has a rational root then it must be of the form:



Where is an integer factor of and is an integer factor of

Using that, the only possible rational factors of



are



Use synthetic division to test these 16 trial divisors until you either find one that divides the original cubic polynomial evenly, leaving you with the successful trial divisor as one factor and a quotient consisting of a quadratic trinomial as another (and hopefully further factorable) factor, or you exhaust all of the possibilities and thereby determine that your denominator is prime.

If you need a refresher on Synthetic Division, see:

Purple Math: Synthetic Division (There are 4 pages -- read them all).

Write back and let me know how you make out.

John

My calculator said it, I believe it, that settles it
The Out Campaign: Scarlet Letter of Atheism


RELATED QUESTIONS

Please help me out with this math. The numerator of a fraction is 5 less than its... (answered by ikleyn,MathTherapy)
we have been working on this problem but cannot figure it out... The ratio of the... (answered by askmemath)
The numerator of a fraction is larger than its denominator by 4. If we add 1 to its... (answered by josgarithmetic)
The denominator of a fraction in its simplest form is greater than the numerator by 5. If (answered by greenestamps)
I am trying to figure out the domain for this problem g(x)= 9 5-7x The 9 is... (answered by edjones)
Hi! I have this word problem that I've been trying to figure out for awhile. My... (answered by ankor@dixie-net.com,MathLover1,ikleyn)
The numerator of a certain fraction is 3 less than the denominator. If the numerator is... (answered by richwmiller)
The denominator of a fraction is 8 more than the numerator. If 3 is added to both the... (answered by mananth)
the numerator of the fraction is one less than twice the denominator. If 3 is added to... (answered by josgarithmetic,Theo,MathTherapy)