Mathematical Operations with Numbers in PHP

Addition:

php<?php
  $a = 1 + 2;
  echo $a; // will output 3
?>

Subtraction:

php<?php
  $b = 3 - 2;
  echo $b; // will output 1
?>

Multiplication:

php<?php
  $c = 3 * 2;
  echo $c; // will output 6
?>

Division:

php<?php
  $d = 4 / 2;
  echo $d; // will output 2
?>

Задание 1

Create a variable $a. Write the sum of numbers 1, 2 and 3 into it. Using the echo command, output the contents of the variable $a to the screen.