Answer :

To simplify the expression [tex]\(5ab + 9ab - ab\)[/tex], follow these steps:

1. Identify the like terms: In this expression, [tex]\(5ab\)[/tex], [tex]\(9ab\)[/tex], and [tex]\(-ab\)[/tex] are all like terms because they all contain the same variables [tex]\(a\)[/tex] and [tex]\(b\)[/tex].

2. Combine the coefficients: Add the coefficients of these like terms together. The coefficients are the numerical parts in front of the [tex]\(ab\)[/tex]:
[tex]\[ 5 + 9 - 1 \][/tex]

3. Perform the addition and subtraction:
[tex]\[ 5 + 9 = 14 \][/tex]
[tex]\[ 14 - 1 = 13 \][/tex]

4. Attach the variable part [tex]\(ab\)[/tex] to the result:
[tex]\[ 13ab \][/tex]

So, the simplified expression for [tex]\(5ab + 9ab - ab\)[/tex] is [tex]\(13ab\)[/tex].

Thus, the correct answer is:
[tex]\[ \boxed{13ab} \][/tex]