The expression is
[tex]AUD/1.38 = USD[/tex]
Step by step conversion is as following;
1 USD = 1.38 AUD, or its reciprocal
Where,
1.38 recent currency rate
AUD = Australian dollar
USD = US dollar
So, by rearranging
[tex]1 AUD = 1/1.38 USD[/tex]
Then
[tex]22AUD/1.38 = 15.94 USD[/tex]
The answer is
[tex]22A UD = 15.94 USD[/tex]