$\begin{array}{1 1}p_{total}=p_A^*+(p_A^*-P_B^*)x_B\\p_{total}=p_B^*+(p_A^*-P_B^*)x_A\\p_{total}=p_A^*+(p_B^*-P_A^*)x_A\\p_{total}=p_B^*+(p_B^*-P_A^*)x_B\end{array} $