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 [tex]\((x^4 + 5x^3 - 3x - 15)\)[/tex] divided by [tex]\((x^3 - 3)\)[/tex], we can perform polynomial division. Let's break it down step-by-step:

1. Set up the division: We're dividing [tex]\(x^4 + 5x^3 - 3x - 15\)[/tex] by [tex]\(x^3 - 3\)[/tex].

2. Divide the leading terms:
- Divide the leading term of the dividend [tex]\(x^4\)[/tex] by the leading term of the divisor [tex]\(x^3\)[/tex].
- This gives us [tex]\(x\)[/tex].

3. Multiply and subtract:
- Multiply the entire divisor [tex]\(x^3 - 3\)[/tex] by the result from step 2, which is [tex]\(x\)[/tex]. This gives [tex]\(x^4 - 3x\)[/tex].
- Subtract [tex]\(x^4 - 3x\)[/tex] from the original dividend [tex]\(x^4 + 5x^3 - 3x - 15\)[/tex].

4. Calculate subtraction:
- Performing the subtraction, we find:
[tex]\[
(x^4 + 5x^3 - 3x - 15) - (x^4 - 3x) = 5x^3 - 15
\][/tex]

5. Repeat the process:
- Now, consider [tex]\(5x^3 - 15\)[/tex]. Divide [tex]\(5x^3\)[/tex] by [tex]\(x^3\)[/tex], which gives you [tex]\(5\)[/tex].
- Multiply [tex]\(x^3 - 3\)[/tex] by [tex]\(5\)[/tex] to get [tex]\(5x^3 - 15\)[/tex].
- Subtract [tex]\(5x^3 - 15\)[/tex] from [tex]\(5x^3 - 15\)[/tex], which results in 0, indicating the remainder is zero.

As a result of the division, the quotient is [tex]\(x + 5\)[/tex].

Therefore, the quotient of [tex]\(\left(x^4 + 5x^3 - 3x - 15\right)\)[/tex] and [tex]\(\left(x^3 - 3\right)\)[/tex] is [tex]\(\boxed{x + 5}\)[/tex].