Answer :

To find the value of the expression [tex]\(\frac{x+y}{4} - \frac{9}{2z}\)[/tex] when [tex]\(x = 2\)[/tex], [tex]\(y = 4\)[/tex], and [tex]\(z = -3\)[/tex], follow these steps:

1. Substitute the values into the expression:

The given expression is:

[tex]\[ \frac{x + y}{4} - \frac{9}{2z} \][/tex]

Substituting [tex]\(x = 2\)[/tex], [tex]\(y = 4\)[/tex], and [tex]\(z = -3\)[/tex]:

[tex]\[ \frac{2 + 4}{4} - \frac{9}{2 \times (-3)} \][/tex]

2. Simplify the numerator and denominator separately:

- First, calculate [tex]\(x + y\)[/tex]:

[tex]\[ 2 + 4 = 6 \][/tex]

- Then, calculate the denominator of the second term:

[tex]\[ 2 \times (-3) = -6 \][/tex]

3. Form the simplified expression:

Substitute these results back into the expression:

[tex]\[ \frac{6}{4} - \frac{9}{-6} \][/tex]

4. Simplify each term:

- Simplify [tex]\(\frac{6}{4}\)[/tex]:

[tex]\[ \frac{6}{4} = \frac{3}{2} = 1.5 \][/tex]

- Simplify [tex]\(\frac{9}{-6}\)[/tex]:

[tex]\[ \frac{9}{-6} = -1.5 \][/tex]

5. Combine the terms:

Now, the expression is:

[tex]\[ 1.5 - (-1.5) \][/tex]

Simplifying this:

[tex]\[ 1.5 + 1.5 = 3.0 \][/tex]

Therefore, the value of the expression [tex]\(\frac{x+y}{4} - \frac{9}{2z}\)[/tex] when [tex]\(x = 2\)[/tex], [tex]\(y = 4\)[/tex], and [tex]\(z = -3\)[/tex] is [tex]\(\boxed{3.0}\)[/tex].