Answer :

To find the value of the expression [tex]\((3x - 12) - \left(\frac{1}{2}xy - 10\right)\)[/tex] for [tex]\(x = 3\)[/tex] and [tex]\(y = 6\)[/tex], we will follow these steps:

1. Substitute the given values: Begin by substituting [tex]\(x = 3\)[/tex] and [tex]\(y = 6\)[/tex] into the expression.

2. Simplify the components: Compute the value of each part of the expression.

Let's break it down step by step:

### Step 1: Substitute [tex]\( x \)[/tex] and [tex]\( y \)[/tex] into the expression

The expression given is:
[tex]\[ (3x - 12) - \left( \frac{1}{2}xy - 10 \right) \][/tex]

Substituting [tex]\(x = 3\)[/tex] and [tex]\(y = 6\)[/tex] into the expression, we get:
[tex]\[ (3 \cdot 3 - 12) - \left( \frac{1}{2} \cdot 3 \cdot 6 - 10 \right) \][/tex]

### Step 2: Simplify the components

Simplify inside the parentheses:
[tex]\[ 3 \cdot 3 = 9 \][/tex]
[tex]\[ \frac{1}{2} \cdot 3 \cdot 6 = 9 \][/tex]

Substituting these values back into the expression, we have:
[tex]\[ (9 - 12) - (9 - 10) \][/tex]

Simplify each part:
[tex]\[ 9 - 12 = -3 \][/tex]
[tex]\[ 9 - 10 = -1 \][/tex]

So the expression now looks like:
[tex]\[ -3 - (-1) \][/tex]

Simplify the overall expression:
Subtracting a negative is the same as adding the positive:
[tex]\[ -3 + 1 = -2 \][/tex]

So, the value of the expression [tex]\((3x - 12) - \left( \frac{1}{2}xy - 10 \right)\)[/tex] for [tex]\(x = 3\)[/tex] and [tex]\(y = 6\)[/tex] is:
[tex]\[ -2 \][/tex]

Therefore, the correct answer is [tex]\(-2\)[/tex].