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 [tex]\((x^4 + 5x^3 - 3x - 15)\)[/tex] when divided by [tex]\((x^3 - 3)\)[/tex], we can perform polynomial long division. Here's how it works:

1. Setup the Division: Place the dividend [tex]\(x^4 + 5x^3 - 3x - 15\)[/tex] under the division bar and the divisor [tex]\(x^3 - 3\)[/tex] outside.

2. First Division Step:
- Divide the first term of the dividend [tex]\(x^4\)[/tex] by the first term of the divisor [tex]\(x^3\)[/tex], which gives [tex]\(x\)[/tex].
- Multiply the entire divisor [tex]\(x^3 - 3\)[/tex] by [tex]\(x\)[/tex], resulting in [tex]\(x^4 - 3x\)[/tex].
- Subtract [tex]\(x^4 - 3x\)[/tex] from the dividend, resulting in a new polynomial: [tex]\(5x^3 - 3x - 15 - (x^4 - 3x) = 5x^3 - 15\)[/tex].

3. Second Division Step:
- Divide the new leading term [tex]\(5x^3\)[/tex] by the leading term of the divisor [tex]\(x^3\)[/tex], which gives [tex]\(+5\)[/tex].
- Multiply the divisor [tex]\(x^3 - 3\)[/tex] by [tex]\(5\)[/tex], resulting in [tex]\(5x^3 - 15\)[/tex].
- Subtract to update the remainder: [tex]\(5x^3 - 15 - (5x^3 - 15) = 0\)[/tex].

Since our remainder is 0, the division ends here.

Thus, the quotient of the polynomial [tex]\((x^4 + 5x^3 - 3x - 15)\)[/tex] divided by [tex]\((x^3 - 3)\)[/tex] is [tex]\(x + 5\)[/tex].

Therefore, the correct quotient is [tex]\(x + 5\)[/tex].