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 find the quotient of the polynomial division [tex]\((x^4 + 5x^3 - 3x - 15) \div (x^3 - 3)\)[/tex] using polynomial long division.

### Step 1: Set it up
First, we write the dividend [tex]\(x^4 + 5x^3 - 3x - 15\)[/tex] and the divisor [tex]\(x^3 - 3\)[/tex]. We need to divide the highest degree term in the dividend by the highest degree term in the divisor.

### Step 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].

[tex]\[ \frac{x^4}{x^3} = x \][/tex]

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

### Step 3: Multiply and subtract
- 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 dividend:

[tex]\[
(x^4 + 5x^3 - 3x - 15) - (x^4 - 3x) = 5x^3 + 0x^2 - 15
\][/tex]

### Step 4: Repeat the process
- Now divide the new leading term [tex]\(5x^3\)[/tex] by the leading term of the divisor [tex]\(x^3\)[/tex].

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

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

- Multiply the entire divisor by [tex]\(5\)[/tex]:

[tex]\[ 5(x^3 - 3) = 5x^3 - 15 \][/tex]

- Subtract this from the current dividend:

[tex]\[
(5x^3 + 0x^2 - 15) - (5x^3 - 15) = 0x^2 + 0
\][/tex]

### Conclusion
Since there is no remainder left and no more terms of higher degree than the divisor in the dividend, we can stop here. The quotient of the division is:

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

The answer is [tex]\(x + 5\)[/tex].