Change output to make example run

`welcome` constant doesn't exist in this example. Either add the welcome constant into the example and change the shell output or do what is done here and print the array of each constant to make the example run.

Author: HisashiQ

docs/tutorials/1-basics/basic_math_operations/README.rst

@@ -78,7 +78,7 @@ The ``session``, which is the environment for running the operations, is execute
     # Run the session
     with tf.Session() as sess:
         writer = tf.summary.FileWriter(os.path.expanduser(FLAGS.log_dir), sess.graph)
-        print("output: ", sess.run(welcome))
+        print("output: ", sess.run([a,b,x,y]))
 
     # Closing the writer.
     writer.close()
@@ -94,11 +94,7 @@ The results for running in the terminal is as bellow:
 
 .. code:: shell
 
-        a = 5.0
-        b = 10.0
-        a + b = 15.0
-        a/b = 0.5
-
+        [5.0, 10.0, 15.0, 0.5]
 
 
 If we run the Tensorboard using ``tensorboard --logdir="absolute/path/to/log_dir"`` we get the following when visualiaing the ``Graph``: