This is exactly the same deal as the most recent question you asked.
"Evaluate each function for x = 8". In other words, this is saying, calculate the result for each function, replace x with 8. So, that means for every function, you are going to replace x with 8.
k(x) = -5x turns into k(x) = -5(8)
Then you just solve, -5(8) = -40
Since I have answered this question similarly, I ask that you go back to the answer and detailed explanation I gave you earlier.
