If the partial volume of species 1 in a binary solution at constant T and P is given by V = V + aa; find the corresponding equation for V2. What equation for V is consistent with these equations for...

I want the correct answer because I sent the question three times, and each time a solution other than the second, I hope for the correct answer with an explanation of the line

Extracted text: If the partial volume of species 1 in a binary solution at constant T and P is given by V = V + aa; find the corresponding equation for V2. What equation for V is consistent with these equations for the partial volumes?