Non symmetricity of matrix supposed to be.

Consider A,B symmetric matrices (in practice they are 112x112).

I want to calculate C=A^-1(B)A^(-1) numerically.

I guess the most efficient way is: C = mrdivide(mldivide(A,B),A), is this correct?

Now theoretically C should be symmetric again, but is not what can be the issues? Is it a good or bad idea to calculate C as above and then afterwards "symmetrise" it by doing e.g. C=C./2+C'./2 or can this induce an error?