((6 factorial) - 1)/(7 factorial) + ((7 - 6 factorial)/(8 factorial)) code example

Example: factorial of 8

function getFactorial($int)
{
   
    $factorial = 1;
    for ($i = $int; $i > 1; $i--)
    {
        $factorial *= $i;
    }
    echo "The factorial of " . $int . " is " . $factorial . '<br>';
}