Which of the following is a factor of x3−5x2−2x+24

, given that x−3
is one of the linear factors?(1 point)
Responses

x+2
x plus 2

x2−8x+22
x squared minus 8 x plus 22

x+4
x plus 4

x−2

1 answer

To find which of the given options is a factor of the polynomial \( x^3 - 5x^2 - 2x + 24 \) while knowing that \( x - 3 \) is one of its linear factors, we can use polynomial long division or synthetic division.

First, we'll divide the polynomial \( x^3 - 5x^2 - 2x + 24 \) by \( x - 3 \).

Using Synthetic Division: We set up synthetic division with \( 3 \) (the root of \( x - 3 \)):

3 | 1  -5  -2  24
  |     3  -6  -24
  ------------------
    1  -2  -8   0

The result is:

  • Quotient: \( 1x^2 - 2x - 8 \)
  • Remainder: \( 0 \)

Thus, we have: \[ x^3 - 5x^2 - 2x + 24 = (x - 3)(x^2 - 2x - 8) \]

Now, we need to factor \( x^2 - 2x - 8 \).

To factor \( x^2 - 2x - 8 \):

  1. Find two numbers that multiply to \( -8 \) and add to \( -2 \). These numbers are \( -4 \) and \( 2 \).

So, we can factor it as: \[ x^2 - 2x - 8 = (x - 4)(x + 2) \]

Thus, the complete factorization of the polynomial is: \[ x^3 - 5x^2 - 2x + 24 = (x - 3)(x - 4)(x + 2) \]

Now, we can see that \( x + 2 \) and \( x - 4 \) are factors of the polynomial.

Therefore, the correct answer among your options is: \( x + 2 \).