For a VLE diagram of Benzene$/$Toluene $($a near$-$ideal system$).$ Explain why in the P$-$x$-$y diagram, the P$-$x curve looks like a straight line connecting p$1($sat$)$ and p$2($sat$)$ Hint: Start by deriving the expression of the P$-$x curve and see how P is related to the benzene liquid composition $($X$2)$