Max z $=3$x$1+4$x$2+$ x$3+5$x$4$

s$.$t$.$ x$1+2$x$2+$ x$3+2$x$4<=5$

$2$x$1+3$x$2+$ x$3+3$x$4<=8$

x$1,$ x$2,$ x$3,$ x$4>=0$

Use the complementary slackness theorem to find the optimal primal solution.