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 :

Sure, let's solve it step-by-step.

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

1. Set up the division:
[tex]\[
\frac{x^4 + 5x^3 - 3x - 15}{x^3 - 3}
\][/tex]

2. Divide the leading term of the numerator by the leading term of the denominator:
[tex]\[
\frac{x^4}{x^3} = x
\][/tex]
So the first term of the quotient is [tex]\(x\)[/tex].

3. Multiply the entire divisor by this term and subtract from the numerator:
[tex]\[
(x^3 - 3) \cdot x = x^4 - 3x
\][/tex]
Now subtract this from the original polynomial:
[tex]\[
(x^4 + 5x^3 - 3x - 15) - (x^4 - 3x) = 5x^3 - 15
\][/tex]

4. Repeat the process with the new polynomial [tex]\(5x^3 - 15\)[/tex]:
- Divide the leading term by the leading term of the divisor:
[tex]\[
\frac{5x^3}{x^3} = 5
\][/tex]
So the next term of the quotient is [tex]\(5\)[/tex].

- Multiply the entire divisor by this term and subtract:
[tex]\[
(x^3 - 3) \cdot 5 = 5x^3 - 15
\][/tex]
Subtract this from the current polynomial:
[tex]\[
5x^3 - 15 - (5x^3 - 15) = 0
\][/tex]

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

After going through these steps, we find that the correct answer is:
[tex]\[
\boxed{x + 5}
\][/tex]