2/3-(-1/2)

2/3-(-1/2) = 2/3 +1/2

$${\frac{{\mathtt{2}}}{{\mathtt{3}}}}{\mathtt{\,\small\textbf+\,}}{\frac{{\mathtt{1}}}{{\mathtt{2}}}} = {\frac{{\mathtt{4}}}{{\mathtt{6}}}}{\mathtt{\,\small\textbf+\,}}{\frac{{\mathtt{3}}}{{\mathtt{6}}}} = {\frac{{\mathtt{7}}}{{\mathtt{6}}}} = {\mathtt{1}}{\mathtt{\,\small\textbf+\,}}{\frac{{\mathtt{1}}}{{\mathtt{6}}}}$$        =    $$1\frac{1}{6}$$

Gruß radix !