Simple Variable Trouble, Mathcad Prime 2.0

Hi folks,

I'm having a little trouble understanding how to use this software for variables. I defined my equations and my variables, but I still can't get that annoying red box to go away. I am not sure what I'm missing from my worksheet that implies that my "red boxes" are not defined.

I have tried to Google this problem, but it seems so trivial that I cannot find a quick solution for it.

I have attached my Mathcad worksheet so that my problem is easier to see.

Thanks for any and all help.