Getting a $total variable from 2 colums

Question

Goodmorning, I have this piece of code on jquery to add the class "toHide" or "notHide" to a table.

$('#search').keyup(function () {
    var inputString = $("#search").val();
    $('td:first-child').parent().show();
    $('td:first-child').parent().addClass("notHide");
    $('td:first-child').parent().removeClass("toHide");
    $var = $('td:first-child').parent('tr:not(:icontains(' + inputString + ')):not(:contains("Total"))');
    $var.hide();
    $var.addClass('toHide');
    $var.removeClass('notHide')
});

I want this class to recalculate the last "Total"

I will post a image to context: Example

So, for example if I write something on search bar, the "Total: price" subtract the "toHide" price.

EDIT_0- I post my first question with PHP but maybe I can get some variable $total on jquery and substrat to that the with the tag toHide. And then update the total.

I have try with the access to the elements of the table but I dont understand at all the table.row[0]cells[0].innerText

EDIT_1: I have tried with this and I got it, but I need that all of that come from the selected ID tab:

$('#search').keyup(function () {
    var x = [];
    var y = [];
    var $total = 0;
    var inputString = $("#search").val();
    $('td:first-child').parent().show();
    $('td:first-child').parent().addClass("notHide");
    $('td:first-child').parent().removeClass("toHide");
    $var = $('td:first-child').parent('tr:not(:icontains(' + inputString + ')):not(:contains("Total"))');
    $var.hide();
    $var.addClass('toHide');
    $var.removeClass('notHide')
    var e = document.getElementById("labdb").value;
    //var match = document.querySelector("#"+e);
    //alert(match)
    for (var price of document.querySelectorAll('tr.notHide td.price')) {   
           x.push(parseFloat(price.innerText));
    }
    for (var cantidad of document.querySelectorAll('tr.notHide td.quantity')) {
        y.push(parseFloat(cantidad.innerText));
    }    
    for(var i = 0; i <= x.length-1; i++){
        $total += x[i] * y[i];
        
    }
    document.getElementById("total").innerText = $total;
});

I need that querySelectorAll comes from the item ID=e:

var e = document.getElementById("labdb").value;
var match = document.querySelector("#"+e);

Work, but need all of that comes from the ID of the selected tab(labdb.value)