Isla is dividing [tex]3x^3 + x^2 - 12x - 4[/tex] by [tex]x + 2[/tex] using a division table.

\begin{tabular}{|c|c|c|c|c|}
\hline & & \multicolumn{3}{|c|}{Quotient} \\
\hline \multirow{4}{*}{Divisor} & & [tex]3x^2[/tex] & [tex]-5x[/tex] & [tex]-2[/tex] \\
\cline{2-5} & [tex]x[/tex] & [tex]3x^3[/tex] & [tex]-5x^2[/tex] & [tex]-2x[/tex] \\
\cline{2-5} & [tex]+2[/tex] & [tex]6x^2[/tex] & [tex]A[/tex] & [tex]B[/tex] \\
\hline
\end{tabular}

What are the missing values in the table?

A. [tex]A = -10x[/tex]; [tex]B = -4[/tex]
B. [tex]A = -10x[/tex]; [tex]B = 0[/tex]
C. [tex]A = -3x[/tex]; [tex]B = -4[/tex]
D. [tex]A = -3x[/tex]; [tex]B = 0[/tex]



Answer :

We need to determine the missing values [tex]\(A\)[/tex] and [tex]\(B\)[/tex] in Isla's division table while dividing [tex]\(3x^3 + x^2 - 12x - 4\)[/tex] by [tex]\(x + 2\)[/tex].

Here's a structured approach to understanding all the steps involved and finding the missing values:

1. Divide the first term:
- The first term of the dividend [tex]\(3x^3\)[/tex] is divided by the first term of the divisor [tex]\(x\)[/tex]:
[tex]\[ \frac{3x^3}{x} = 3x^2 \][/tex]
- The first term of the quotient is [tex]\(3x^2\)[/tex].

2. Multiply the entire divisor by the first term of the quotient:
- Multiply [tex]\(3x^2\)[/tex] by the divisor [tex]\(x + 2\)[/tex]:
[tex]\[ 3x^2 \cdot (x + 2) = 3x^3 + 6x^2 \][/tex]

3. Subtract the result from the dividend:
- Subtract [tex]\(3x^3 + 6x^2\)[/tex] from [tex]\(3x^3 + x^2 - 12x - 4\)[/tex]:
[tex]\[ (3x^3 + x^2 - 12x - 4) - (3x^3 + 6x^2) = x^2 - 6x - 4 \][/tex]

4. Divide the next term:
- Divide [tex]\(x^2\)[/tex] by [tex]\(x\)[/tex]:
[tex]\[ \frac{x^2}{x} = x \][/tex]
- Subtract the term [tex]\(6x^2\)[/tex] from both sides to continue the division:
[tex]\[ (x^2 - 6x - 4) - x = -5x^2 - 12x - 4 \][/tex]

5. Repeat the process for subsequent terms:
- The details for the further steps will also solve and correct below:
- After dividing [tex]\(x^2-6x\)[/tex] by [tex]\(x\)[/tex], we get the term [tex]\(-5x\)[/tex].
- Multiply [tex]\(-5x\)[/tex] by the divisor [tex]\(x + 2\)[/tex]:
[tex]\[ -5x(x + 2) = -5x^2 - 10x \][/tex]
- Subtract the result from the previous remainder:
[tex]\[ (x^2 - 6x) - (-5x^2 - 10x) = x^2 + 5x^2 + 4x = 6x^2 + 4x \][/tex]
6. Finally, the last quotient term is found by subtracting the final multiplication:
- Divide [tex]\(6x^2 + 4x - 4\)[/tex] by [tex]\(x + 2\)[/tex].
[tex]\[ -2(x+2) = -2x - 4 = B \][/tex]
The [tex]\(A\)[/tex] division value:
[tex]\[ 4x \cdot 2 = 2^2 = -10x \][/tex]

Therefore, the correct values are
[tex]\[ A = -10x, \quad B = -4 \][/tex]

So, the missing values in the table are:
[tex]\[ \boxed{A = -10x; B = -4} \][/tex]