Answer :

To find the value of the expression [tex]\(5y - z\)[/tex] when [tex]\(y = 5\)[/tex] and [tex]\(z = 7\)[/tex], we need to follow these steps:

1. Substitute the given values into the expression:
[tex]\[ 5y - z \][/tex]

Here, [tex]\(y = 5\)[/tex] and [tex]\(z = 7\)[/tex].

2. Replace [tex]\(y\)[/tex] with 5:
[tex]\[ 5 \times 5 - z \][/tex]

3. Perform the multiplication:
[tex]\[ 25 - z \][/tex]

4. Replace [tex]\(z\)[/tex] with 7:
[tex]\[ 25 - 7 \][/tex]

5. Perform the subtraction:
[tex]\[ 18 \][/tex]

Therefore, the value of the expression [tex]\(5y - z\)[/tex] when [tex]\(y = 5\)[/tex] and [tex]\(z = 7\)[/tex] is [tex]\(18\)[/tex].