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 solve this problem, we need to perform polynomial long division to find the quotient of [tex]\((x^4 + 5x^3 - 3x - 15)\)[/tex] divided by [tex]\((x^3 - 3)\)[/tex].

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

1. Initial Setup:
- Dividend: [tex]\(x^4 + 5x^3 - 3x - 15\)[/tex]
- Divisor: [tex]\(x^3 - 3\)[/tex]

2. Division Process:

- First Term:
- Divide the first term of the dividend by the first term of the divisor: [tex]\(\frac{x^4}{x^3} = x\)[/tex].
- Multiply the entire divisor [tex]\((x^3 - 3)\)[/tex] by [tex]\(x\)[/tex]: [tex]\(x(x^3 - 3) = x^4 - 3x\)[/tex].
- Subtract this result from the original dividend:
[tex]\[
(x^4 + 5x^3 - 3x - 15) - (x^4 - 3x) = 5x^3 - 0x^2 + 0x - 15
\][/tex]

- Second Term:
- Now, divide the new first term of the remainder [tex]\(5x^3\)[/tex] by [tex]\(x^3\)[/tex]: [tex]\(\frac{5x^3}{x^3} = 5\)[/tex].
- Multiply the entire divisor by [tex]\(5\)[/tex]: [tex]\(5(x^3 - 3) = 5x^3 - 15\)[/tex].
- Subtract this result from the current remainder:
[tex]\[
(5x^3 + 0x^2 + 0x - 15) - (5x^3 - 15) = 0
\][/tex]

Since the remainder is [tex]\(0\)[/tex], the division results in a quotient of:
[tex]\[ x + 5 \][/tex]

3. Conclusion:
- The quotient of the division of [tex]\((x^4 + 5x^3 - 3x - 15)\)[/tex] by [tex]\((x^3 - 3)\)[/tex] is [tex]\(x + 5\)[/tex].

Therefore, the correct answer from the given options is [tex]\(x + 5\)[/tex].