L = total number of slices for Luke
K = total number of slices for Kira
A = total number of slices for Ali
[tex]\stackrel{\textit{two thirds of all slices}}{\cfrac{2}{3}L}=4\implies 2L=12\implies L=\cfrac{12}{2}\implies L=6 \\\\\\ \stackrel{\textit{two thirds of all slices}}{\cfrac{2}{3}K}=6\implies 2K=18\implies K=\cfrac{18}{2}\implies K=9 \\\\\\ \stackrel{\textit{two thirds of all slices}}{\cfrac{2}{3}A}=8\implies 2A=24\implies A=\cfrac{24}{2}\implies A=12[/tex]
