Beginning game development with LibGDX - moving an image

gistfile1.txt

float posX = 0;
@Override
public void render() {
    Gdx.gl.glClearColor(1, 0, 0, 1);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
    batch.begin();
    batch.draw(img, posX, 0);
    batch.end();
    // The time it took to render the last frame on screen
    float delta = Gdx.graphics.getDeltaTime();
    float speed = 100;
    posX += delta * speed;
}