One of the factors of the polynomial x^3 + 5x^2 + 6x is (x^2 + 3x). What is the other factor?

x-2, x+2, x+1 or x-1?

Question

One of the factors of the polynomial x^3 + 5x^2 + 6x is (x^2 + 3x). What is the other factor?

x-2, x+2, x+1 or x-1?

kkutie7 · Answer

Multiply each one of the answers with (x^2+3x) and see what get you to the original polynomial.

anonymous · Answer

Well you need an x to get back x^3 and you need a 2 to get 6x (using FOIL method and just looking at first and last). Now for the sign. If you have a minus sign between them for the second factor to be x-2, then you get a minus sign for the middle term. So it must be x+2 to get the outer and inner to be positive 5x^2.

Even if you couldn't analyze it like that, you had the two factors. You could've just multiplied the choice individually to the factor already given in the problem. No excuses really for not trying that.