Same question but different way!

Question

HTML:
<p>x</p>

I want to relate it with js and the output should be 20,where x=5

Answer 1

You should learn vue / angular to perform these kinds of view-controller bindings!

Both of them are very simple and great libraries.

Answer 2

const pNode = document.querySelector("p");
let x = 5;

pNode.innerHTML=x*4;