title: Problem in coding argument to create output
body: <p>I need to make this equation into 9. An example of the following can be seen below:</p>
  <h1>a^2-b^2 = (a+b)*(a-b)</h1>
  <h1>5^2 - 4^2 = (5+4)(5-4) = 9</h1>
  <p>and the code must be in multiplier using</p>
  <h1>print(mult_numbers(add_numbers(5,4), sub_numbers(5,4)))</h1>
  <pre><code>def add_numbers(a, b):
      result = a + b
      return result
  
  def sub_numbers(a, b):
       Write code to return sum of a and b
      result =  None #Replace None with your code
      return result
  </code></pre>
  <p>Can someone help me to re-write the code?</p>
  <pre><code>def add_numbers(5, 4):
      result = 5 + 4
      return result
  
  def sub_numbers(5, 4):
      # Write code to return sum of a and b
      result =  5-4
      return result
  print(mult_numbers(add_numbers(5,4), sub_numbers(5,4)))
  </code></pre>
  <p>I am receiving :</p>
  <h1>File &quot;&quot;, line 1</h1>
  <pre><code>def add_numbers(5, 4):
                  ^
  </code></pre>
  <p>SyntaxError: invalid syntax</p>