❔ ✅ Equation in code

public static int GetLevel(decimal XP)
        {
            double level = 4 * Math.Pow((double)XP, 0.2794) - 5;
            level = Math.Floor(level);
            return (int)level;
        }

        public static double GetXpForLevel(int level)
        {
            double XP = Math.Pow((level + 5) / 4, 5000 / 1397); //gives wrong output
            return XP;
        }