College

The quotient of [tex]\left(x^4+5x^3-3x-15\right)[/tex] and [tex]\left(x^3-3\right)[/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 [tex]\((x^4 + 5x^3 - 3x - 15) \div (x^3 - 3)\)[/tex], we 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]

So, the first term of the quotient is [tex]\(x\)[/tex].

2. Multiply the entire divisor by this term and subtract from the dividend:

[tex]\[
\text{Multiply: } x(x^3 - 3) = x^4 - 3x
\][/tex]
[tex]\[
\text{Subtract: } (x^4 + 5x^3 - 3x - 15) - (x^4 - 3x) = 5x^3 + 0x - 15
\][/tex]

3. Repeat the process with the new polynomial (remainder):

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

So, the next term of the quotient is [tex]\(5\)[/tex].

4. Multiply the entire divisor by this new term and subtract:

[tex]\[
\text{Multiply: } 5(x^3 - 3) = 5x^3 - 15
\][/tex]
[tex]\[
\text{Subtract: } (5x^3 - 15) - (5x^3 - 15) = 0
\][/tex]

The subtraction results in zero, indicating we have no remainder.

The polynomial division is complete, and the quotient is the sum of the terms obtained during the division, which is:

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

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

Answer: [tex]\(x + 5\)[/tex]