Connect with knowledgeable experts and enthusiasts on IDNLearn.com. Ask any question and receive timely, accurate responses from our dedicated community of experts.

Select all the correct answers.

Which of these are factors of this polynomial?

[tex]\[ -3x^3 + 15x^2 + 3x - 15 \][/tex]

A. [tex]\((3x-1)\)[/tex]

B. [tex]\((x+5)\)[/tex]

C. [tex]\(-3\)[/tex]

D. [tex]\((x-5)\)[/tex]

E. [tex]\((x-1)\)[/tex]

F. [tex]\(3x\)[/tex]


Sagot :

Certainly! Let's determine the factors of the polynomial [tex]\( -3 x^3 + 15 x^2 + 3 x - 15 \)[/tex]. We'll do this by using polynomial factorization methods, specifically by testing the given factors to see if they divide the polynomial without leaving a remainder.

First, write the polynomial in question:
[tex]\[ P(x) = -3 x^3 + 15 x^2 + 3 x - 15 \][/tex]

Now let's test each of the given possible factors to see which ones are actual factors of the polynomial.

1. Factor: [tex]\( \pi + 1 \)[/tex]
- This is a constant and not a suitable factor for a polynomial in [tex]\( x \)[/tex]. Factors of a polynomial should also be polynomial expressions in [tex]\( x \)[/tex].

2. Factor: [tex]\( 3x - 1 \)[/tex]
- To test if [tex]\( 3x - 1 \)[/tex] is a factor, substitute [tex]\( x = \frac{1}{3} \)[/tex] into the polynomial:
[tex]\[ P\left(\frac{1}{3}\right) = -3 \left(\frac{1}{3}\right)^3 + 15 \left(\frac{1}{3}\right)^2 + 3 \left(\frac{1}{3}\right) - 15 = -3 \left(\frac{1}{27}\right) + 15 \left(\frac{1}{9}\right) + 1 - 15 = -\frac{1}{9} + \frac{5}{3} + 1 - 15 = -\frac{1}{9} + \frac{15}{9} + 1 - 15 = \frac{14}{9} + 1 - 15 = \frac{23}{9} - 15 = \frac{23}{9} - \frac{135}{9} = -\frac{112}{9} \neq 0 \][/tex]
Since [tex]\( P\left(\frac{1}{3}\right) \neq 0 \)[/tex], [tex]\( 3x - 1 \)[/tex] is not a factor.

3. Factor: [tex]\( x + 5 \)[/tex]
- To test if [tex]\( x + 5 \)[/tex] is a factor, substitute [tex]\( x = -5 \)[/tex] into the polynomial:
[tex]\[ P(-5) = -3(-5)^3 + 15(-5)^2 + 3(-5) - 15 = -3(-125) + 15(25) - 15 - 15 = 375 + 375 - 15 - 15 = 720 \neq 0 \][/tex]
Since [tex]\( P(-5) \neq 0 \)[/tex], [tex]\( x + 5 \)[/tex] is not a factor.

4. Factor: [tex]\( -3 \)[/tex]
- Since [tex]\(-3\)[/tex] is a numeric constant (a factor that cannot be zero as a polynomial zero), it cannot be considered a suitable factor in this context. Factors of a polynomial in [tex]\( x \)[/tex] should involve [tex]\( x \)[/tex].

5. Factor: [tex]\( x - 5 \)[/tex]
- To test if [tex]\( x - 5 \)[/tex] is a factor, substitute [tex]\( x = 5 \)[/tex] into the polynomial:
[tex]\[ P(5) = -3(5)^3 + 15(5)^2 + 3(5) - 15 = -3(125) + 15(25) + 15 - 15 = -375 + 375 + 15 - 15 = 0 \][/tex]
Since [tex]\( P(5) = 0 \)[/tex], [tex]\( x - 5 \)[/tex] is a factor.

6. Factor: [tex]\( x - 1 \)[/tex]
- To test if [tex]\( x - 1 \)[/tex] is a factor, substitute [tex]\( x = 1 \)[/tex] into the polynomial:
[tex]\[ P(1) = -3(1)^3 + 15(1)^2 + 3(1) - 15 = -3(1) + 15(1) + 3 - 15 = -3 + 15 + 3 - 15 = 0 \][/tex]
Since [tex]\( P(1) = 0 \)[/tex], [tex]\( x - 1 \)[/tex] is a factor.

7. Factor: [tex]\( 3x \)[/tex]
- For [tex]\( 3x \)[/tex] to be a factor, the polynomial should be zero when [tex]\( x = 0 \)[/tex]:
[tex]\[ P(0) = -3(0)^3 + 15(0)^2 + 3(0) - 15 = -15 \neq 0 \][/tex]
Since [tex]\( P(0) \neq 0 \)[/tex], [tex]\( 3x \)[/tex] is not a factor.

In conclusion, the correct factors of the polynomial [tex]\( -3 x^3 + 15 x^2 + 3 x - 15 \)[/tex] among the given options are:
- [tex]\( x - 5 \)[/tex]
- [tex]\( x - 1 \)[/tex]