On the reduced semi-empirical equations of state of the form $\tilde{V}=\tilde{V}(\tilde{P},\tilde{T})$

In the framework of the thermodynamic approach to the study of macrosystems using the Cardano method, three two-parameter equations of state are considered. Basing on the given forms of the form $\tilde{P}=\tilde{P}(\tilde{V},\tilde{T})$ of the Redlich–Kwong, Berthelot and Van der Waals equations of state, the explicit forms of their functional representations of the form $\tilde{V}=\tilde{V}(\tilde{P},\tilde{T})$ are determined.