Is there a way to to do the following:

such that Uranium containing the presubsup expression  displays the values contained in A, Z and X instead of just the letters?

(Edit):

I can, however, get it to work using the (A)[b]^(c) expression  from the same palette:

Though I don't understand why it works with one and not the other.

The differential equation I'm solving for is:

Wolfram Alpha has a normalcdf() function, which with parameters reads: normalcdf(x₁, x₂, µ, σ). How would I go about acheiving the same in Maple?

In trying to solve for a difference quotient, I've entered the following:

Why does the second solution appear in the way I want, but not the first? Is there any way to get the first to display in the same way as the second?

Thanks in advance.