# some text flush left and other text flush right on same line

Equations need to be flush left and equation numbers flush right. The distance between equations and numbers will vary, depending on the length of the equations.

This could be done with tables but I want to know if there are other ways. Also, I am not asking about justification. There needs to be blank space between text on the left and text on the right.

Is there a name for this type of alignment? What is the easiest way to do this?