But that IS the exact answer, the correct answer. Did you want MATLAB to produce the wrong answer?
Maybe what you wanted is for MATLAB to "expand" that product? Did you tell MATLAB to do so? How might you do that?
What would the result be if you tried this?
Its just a thought.
A good way to learn about the tools in MATLAB is to read about all of the functions in a toolbox. Kind of like reading the manual.