Squaring the Binomial

[MullenJohn]

Help,

Using my HP Prime calculator I am try to square the binomial (12*c^4 + 0.25*a^6*c)^2.

I was expecting something like (a^2 + B^2 + c) but I am getting only a number like 2.9887...

Please tell me how to expand the binomial with just the literals.

Thanks - Cheers!