As long as the cooked steak has been refrigerated for those five days then the steak should be safe to eat.
It's best to eat the cooked steak either the same day or within a few days of refrigerating it because the steak can lose it's flavor and may not taste as good.
But as long as the cooked steak smells good has no mold on it or anything and tastes good then it's likely safe to eat.
If the steak has been in the refrigerator longer than 5 days then I would be hesitant to eat it.
But I have eaten steak after 5 days in the refrigerator and I never got sick from it.
I put the steak in the oven to reheat it and then if there were any bacteria on the steak then the oven temperature should kill the bacteria so it would not be harmful.