title: How in Java script to find the necessary number from three numbers?
body: <p>I have four numbers 15 30 70 140. and "x", which can get any number, how to say if ()? that if x is equal to 15 30 70 140, then true, if not, then false.</p>
  
  <pre><code>const x =....;
  if(x===?){....}else{....}
  </code></pre>