how do you factor x

^{2 }-9x-16,200how do you factor x^{2 }-9x-16,200

Tutors, please sign in to answer this question.

Las Vegas, NV

by calculating b2-4ac from quadratic formula. If b2-4ac doesn't become perfect square, it is prime.

Decatur, GA

x^2 – 9x

-16,200

First, the

coefficient of the first term (1) is prime, so we will not be able to factor a

constant out. Next, there is no variable in the last term (16,200 (there is no

"x")), so we cannot factor out a variable.

Next, we

must find factors of 16,200 that differ by 9, so that when added together we

can get the -9 value that we need in the middle term.

Since

122*131=15,982 (which is less than 16,200), and 123*132=16,236 (which is greater than 16,200), these would be the possible factors of 16,200 that might have combined to produce the -9 that we were after. Since neither pair are actually factors of 16,200, it would seem that 16,200 does not have factors that differ exactly by a value of 9. Therefore, the polynomial cannot be factored. It must be prime.

Scottsdale, AZ

Since b^2 - 4ac =(-9)^2 - 4(1)(-16,200) = 64,881 is not a perfect square, x^2 - 9x - 16,200 is prime.However, you can factor it in irrational domain by completing the square or using quadratic formula.

Here is the way by completing the square:

x^2-9x+(9/2)^2 - (9/2)^2 - 16,200

= (x-4.5)^2 - 16,220.25

= [x-4.5+sqrt(16,220.25)][x-4.5-sqrt(16,220.25)]

Robert E.

Experienced Physics and Math Tutor

Jamaica, NY

4.9
(495 ratings)

Nikunj P.

Math and Science Specialist, Over 14 Years of Educational Experience

Scarsdale, NY

4.9
(178 ratings)

Jing X.

IVY-graduate specializing in SAT, ACT, Math and College App

Brooklyn, NY

4.9
(76 ratings)

- Algebra 4747
- Algebra 1 3862
- Math 9039
- Factoring Polynomials 113
- Algebra 2 3243
- Factorization 21
- Factoring By Grouping 19
- Math Help 5031
- Quadratic Equations 482
- Polynomials 313