Operaciones matemáticas. Sumatorio.

Codigo:

//Sumatorio
package sumatorio;
import java.util.Scanner;
public class Sumatorio {
    public static void main(String[] args) {
        //Inicializar variables
        int[] x = new int[5];
        for (int i = 1; i < x.length; i++) {
            System.out.println("Introduce valor X" + i + ":");
            Scanner leer = new Scanner(System.in);
            x[i] = Integer.parseInt(leer.next());
        }
        int n = x.length;
        int m = 1;
        int sumatorio = 0;
        String formula = "";
        //Sumatorio
        for (int i = m; i < n; i++) {               
            sumatorio += x[i];
            formula += " + " + x[i];
        }
        System.out.println("\n∑ =" + formula.substring(2) + " = " + sumatorio);
    }
}


Resultado:

run:
Introduce valor X1:
23
Introduce valor X2:
61
Introduce valor X3:
7
Introduce valor X4:
99

∑ = 23 + 61 + 7 + 99 = 190
BUILD SUCCESSFUL (total time: 11 seconds)