Hello!
When a variable equals a number, you substitute in that number wherever the variable is. So, in this case, since k = 3, substitute in 3 wherever k appears in the equation.
15 / k
15 / 3
Now, divide 15 by 3. To do this, ask yourself how many times 3 goes into 15. It would be 5, as 3 + 3 + 3 + 3 + 3 = 15. (So essentially 5 3's go into 15, so it equals 5)
15 / 3 = 5
Therefore, your answer is 5.
Hope this helps!
