How can I create variable matrix

Hi, im new on matlab. ı want to create iterable matrix for solving 3 unknowns equation. like; first matrix x(0)=[1;2;3] second matrix x(1)=[4;5;6]

syms a b c

x(k)=[1;2;3]; x(k+1)=[4;5;6];

f=inline('a+b+c'); f(x(k));

Please help...