What version of Mathcad are you using? I would like to provide for you some Mathcad worksheet example. Here's how it looks:
Here you need to work with a text region (in main menu go to "Insert" -> "Text Region") and to insert into him mathematical region when necessary ("Insert" -> "Math Region"):
Use a boolean equal ("Equal to", hotkey "Ctrl + =") when specifying the function and then choose (by using right mouse button) "View Equality As" -> "Equal":
I think Vladimir has shown the answer for the example you provided, but I think the example you provided may not have been what you originally wanted.
The example you gave was the definition of a function, not an expression. Functions do not have results upon definition because the argument has not been specified. Therefore, the only way we can interpet your example is as a text description, not a live math equation. Vladimir provided a solution to aligning that text.
I think your original question was to align the numerical result of a live equation. I don't know of a way to do that in the equation result. What I do is to show results separately after the definition, and then I align those results with the align tool. It's not perfect because the tool doesn't right justify, only left. However, it does sometimes help to separate the numerical results from the definitions. An example is below:
