Operadores

<?php
//Concatenar
$name = "Guilherme";
$last_name = "Ferreira";
echo $name." ".$last_name;
echo "<br>";
//Soma
$x = 10;
$y = 8;
//$x++ incremneta 1
$x++;
//$y+=3 incremneta 3
$y+=3;
echo $x + $y;
//Subtração
echo "<br>";
$x = 10;
$x--; //decrementa 1
$y-=3; //decremta 3
$y = 8;
echo $x - $y;
//Divisão
$x = 10;
$y = 8;
echo $x / $y;
echo "<br>";
//Multiplicasão
$x = 10;
$y = 8;
echo $x * $y;
echo "<br>";
//Exponencial - introduzido no PHP 5.6
$x = 2;
$y = 3;
echo $x ** $y;
echo "<br>";
//Módulo
$x = 4;
$y = 2;
echo $x % $y;
?>