What is the problem here please :'(

import java.math.*;
import javax.swing.*;

public class Q5
{
    public static void main(String []args)
    {
       double n;
       String Output="";
       int t=0;
       int supervisingyears=0;
       
       for(t=0;t<=25;t++)
       {
           n=220/(1+10 * math.pow(0.83,t));
           if (n<80)
           supervisingyears++;
           output=output+"\n Number of Supervising  Years"+supervisingyears+"\n";
           JOptionPane.showMessageDialog(null,output);
        }
    }
}

Please read the rules and you you would know that code-tags are expected be used by any member, plus you would know that you are supposed to provide proper problem description.

Your problem is math.powthat is supposed to be Math.pow
Java is case sensitive unlike for example html where TABLE, tAbLe and table are still same (even though lower case is recommended by w3c and is sign of weak developers)