Class of Complex Number

void setup () {
  Complex_Number answer;
  int realNum1 = 4;
  int comNum1 = 3;
  int realNum2 = 2;
  int comNum2 = 1;

  answer = new Complex_Number (realNum1, comNum1, realNum2, comNum2);
  println ("("+(realNum1)+"+"+(comNum1)+"i + "+(realNum2)+"+"+(comNum2)+"i) = "+(answer.Addition()));
  println ("("+(realNum1)+"+"+(comNum1)+"i - "+(realNum2)+"+"+(comNum2)+"i) = "+(answer.Subtruction()));
}

void draw () {
}

class Complex_Number {
  int x;
  int y;
  int a;
  int b;
  Complex_Number (int realNum1, int comNum1, int realNum2, int comNum2) {
    this.x = realNum1;
    this.y = comNum1;
    this.a = realNum2;
    this.b = comNum2;
  }
  String Addition () {
    int value1 = (this.x+this.a);
    int value2 = (this.y+this.b);
    String result = (value1)+"+"+(value2)+"i";
    return result;
  }
  String Subtruction () {
    int value1 = (this.x-this.a);
    int value2 = (this.y-this.b);
    String result = (value1)+"+"+(value2)+"i";
    return result;
  }
}