what is a-2/3b1/6c2/9 equivalent to?
$${\mathtt{a}}{\mathtt{\,-\,}}{\frac{{\frac{{\frac{{\mathtt{2}}}{{\mathtt{3}}}}{\mathtt{\,\times\,}}{\mathtt{b1}}}{{\mathtt{6}}}}{\mathtt{\,\times\,}}{\mathtt{c2}}}{{\mathtt{9}}}}$$
Is this your intended question?