Greetings.
The answer is 5.
Explanation:
[tex]\frac{x-6}{3}[/tex]
We want to know the value when x = 21. Therefore, substitute x = 21 in the expression.
[tex]\frac{21-6}{3}[/tex]
Evaluate 21-6 = 15
[tex]\frac{15}{3}[/tex]
Therefore, the answer is 5.
