What is [tex]$x^3 + 3x^2 - 16x - 48$[/tex] divided by [tex]$x + 3$[/tex]?

A. [tex]$x^2 + 6x - 16$[/tex]

B. [tex][tex]$x^2 - 16$[/tex][/tex]

C. [tex]$x^2 + 6x - 12 + \frac{54}{x + 3}$[/tex]

D. [tex]$x^2 + 6x + 2 - \frac{42}{x + 3}$[/tex]



Answer :

To find the quotient when dividing [tex]\(x^3 + 3x^2 - 16x - 48\)[/tex] by [tex]\(x + 3\)[/tex], we can perform polynomial long division or synthetic division.

Let's break down the process of polynomial long division step-by-step:

1. Set up the division:
We are dividing [tex]\(x^3 + 3x^2 - 16x - 48\)[/tex] by [tex]\(x + 3\)[/tex].

2. Divide the leading term:
- Divide the leading term of the dividend [tex]\(x^3\)[/tex] by the leading term of the divisor [tex]\(x\)[/tex]:
[tex]\[ \frac{x^3}{x} = x^2 \][/tex]

3. Multiply and subtract:
- Multiply [tex]\(x^2\)[/tex] by [tex]\(x + 3\)[/tex] and subtract this product from the dividend.
[tex]\[ x^2 \cdot (x + 3) = x^3 + 3x^2 \][/tex]
- Subtract:
[tex]\[ (x^3 + 3x^2 - 16x - 48) - (x^3 + 3x^2) = -16x - 48 \][/tex]

4. Bring down the next term:
- Note that the next term is already considered, so we just perform the division on [tex]\(-16x - 48\)[/tex].

5. Repeat the process:
- Divide the leading term [tex]\(-16x\)[/tex] by [tex]\(x\)[/tex]:
[tex]\[ \frac{-16x}{x} = -16 \][/tex]
- Multiply [tex]\(-16\)[/tex] by [tex]\(x + 3\)[/tex]:
[tex]\[ -16 \cdot (x + 3) = -16x - 48 \][/tex]
- Subtract:
[tex]\[ (-16x - 48) - (-16x - 48) = 0 \][/tex]

So, the quotient is [tex]\(x^2 - 16\)[/tex] and the remainder is 0, meaning the division is exact.

Thus, [tex]\(x^3 + 3x^2 - 16x - 48\)[/tex] divided by [tex]\(x + 3\)[/tex] results in:

[tex]\[ \boxed{x^2 - 16} \][/tex]

Therefore, the correct answer is:
B. [tex]\(x^2 - 16\)[/tex]