Find AC
A=
2 3 0
4 1 6
C=
2 3
0 1
1 0
you can do matrix stuff at wolframalpha.com, as in this case,
AC=
{{2,3,0},{4,1,6}}*{{2,3},{0,1},{1,0}}
= {{4,9},{14,13}}
Just for grins, showing that matrix multiplication is not commutative,
CA={{16,9,18},{4,1,6},{2,3,0}}