The DP stage for $x_2$ carries both constraints that involve $x_2$

Consider the LPP: maximize $Z=3x_1+5x_2$ subject to $x_1\le4$, $x_2\le6$, $3x_1+2x_2\le18$, $x_1,x_2\ge0$. The first stage in the dynamic programming algorithm to solve the above problem involves: