void setup() {
  Serial.begin(9600);
  int x, y1, y2;

  for (x = -10; x <= 10; x++) {
    y1 = x * x + 8;
    y2 = x + 10;
    if (y1 == y2) {
      Serial.print("x="); Serial.print(x);
      Serial.print("y1="); Serial.print(y1);
      Serial.print("y2="); Serial.print(y2);
    }
  }

}

void loop() {
  // put your main code here, to run repeatedly:

}