How to solve equations with functions which contain unknown

Hello everyone! I want to solve equations with functions which contain unknown. The code is shown below:

Looking for the value of As.

Any suggestion?

[per isakson]

It's easier to help if you provide the script as text formated as code rather than as an image.

Suggestion: add As to the list of symbolic variables.

Answer 1

[Mahesh Taparia]

Hi

If 'As' is a known variable then define in your code and if it is unknown and symbolic variable then define using syms function.