Solve Block for Range Variables

Hi everyone,

I'm currently working on a Mathcad document that requires iterations at some point to solve for a value, so I decided to try and use solve blocks. the only problem with this, is that I use several range variables. I read online that you can trick a solve block to work with range variables if you define your range variables as functions, but one of my parameters relies on the sum of a range variable. Does anyone know if it's possible to get this to work?

Thanks for your help,

Talina