College

The quotient of [tex]$x^4 + 5x^3 - 3x - 15$[/tex] and [tex]$x^3 - 3$[/tex] is a polynomial. What is the quotient?

A. [tex]$x^7 + 5x^6 - 6x^4 - 30x^3 + 9x + 45$[/tex]

B. [tex]$x - 5$[/tex]

C. [tex]$x + 5$[/tex]

D. [tex]$x^7 + 5x^6 + 6x^4 + 30x^3 + 9x + 45$[/tex]

Answer :

To find the quotient of the polynomial division of [tex]\(x^4 + 5x^3 - 3x - 15\)[/tex] by [tex]\(x^3 - 3\)[/tex], we will perform polynomial long division.

### Step-by-Step Polynomial Long Division:

1. Divide the first term of the dividend by the first term of the divisor:

[tex]\[
\frac{x^4}{x^3} = x
\][/tex]

2. Multiply the whole divisor by this result:

[tex]\[
x \cdot (x^3 - 3) = x^4 - 3x
\][/tex]

3. Subtract the result from the original dividend:

[tex]\[
(x^4 + 5x^3 - 3x - 15) - (x^4 - 3x) = 5x^3 + 0 - 15
\][/tex]

4. Bring down the next term (if required):

The subtraction resulted in [tex]\(5x^3 - 15\)[/tex].

5. Repeat the process:

- Divide the first term [tex]\(5x^3\)[/tex] by [tex]\(x^3\)[/tex]:

[tex]\[
\frac{5x^3}{x^3} = 5
\][/tex]

- Multiply the entire divisor by this result:

[tex]\[
5 \cdot (x^3 - 3) = 5x^3 - 15
\][/tex]

- Subtract this from what is left:

[tex]\[
(5x^3 - 15) - (5x^3 - 15) = 0
\][/tex]

The remainder is 0 after subtraction, indicating that the division is exact, and the quotient is simply the result from step 1 and step 5:

The quotient is:

[tex]\[
x + 5
\][/tex]

So, the correct answer is [tex]\(x + 5\)[/tex].