How do i add points when the object past a specific coordinate

using UnityEngine;
using System.Collections;

public class score : MonoBehaviour {
	private int scoreValue;
	public GUIText guiScore;
	private Transform Obstacle;


	// Use this for initialization
	void Start () {
		Obstacle = transform;
		scoreValue = 0;
		guiScore.text = "Score: 0";
		
	
	}

	// Update is called once per frame
		void Update () {
		if (Obstacle.position.x <= -19.2 ){
			scoreValue += 10;
			guiScore.text = "Score: " + scoreValue;

this is what i have so far, it adds the points but instead of adding 10 everytime one of the obstacles past the x coordindate it keeps on adding ( think its becuz of the “<”) so i need help in only adding 10 when it “equals” that specific coordinate

Hey, your condition in the update will be true every frame that that condition is met. If you only want the condition to be true once you need an additional check or to move / destroy the obstacle.

bool hasAwardedPoints = false;
void Update ()
{
     if (Obstacle.position.x <= -19.2f  && !hasAwardedPoints)
     {
         scoreValue += 10;
         guiScore.text = "Score: " + scoreValue;
         hasAwardedPoints = true;
     }
}

or

void Update ()
{
     if (Obstacle && Obstacle.position.x <= -19.2f)
     {
         scoreValue += 10;
         guiScore.text = "Score: " + scoreValue;
         Destroy(Obstacle.gameObject);
     }
}

I hope that helps =)