http://calculator.intemodino.com/de/bruchrechner.html
$${\frac{{\mathtt{5}}}{{\mathtt{7}}}}{\mathtt{\,\small\textbf+\,}}{\frac{{\mathtt{6}}}{{\mathtt{7}}}}{\mathtt{\,-\,}}{\frac{{\mathtt{4}}}{{\mathtt{7}}}} = {\mathtt{1}}$$ $${\frac{{\mathtt{9}}}{{\mathtt{11}}}}{\mathtt{\,-\,}}{\frac{{\mathtt{7}}}{{\mathtt{11}}}}{\mathtt{\,\small\textbf+\,}}{\frac{{\mathtt{3}}}{{\mathtt{11}}}}{\mathtt{\,-\,}}{\frac{{\mathtt{1}}}{{\mathtt{11}}}} = {\frac{{\mathtt{4}}}{{\mathtt{11}}}} = {\mathtt{0.363\: \!636\: \!363\: \!636\: \!363\: \!6}}$$
http://calculator.intemodino.com/de/bruchrechner.html
$${\frac{{\mathtt{5}}}{{\mathtt{7}}}}{\mathtt{\,\small\textbf+\,}}{\frac{{\mathtt{6}}}{{\mathtt{7}}}}{\mathtt{\,-\,}}{\frac{{\mathtt{4}}}{{\mathtt{7}}}} = {\mathtt{1}}$$ $${\frac{{\mathtt{9}}}{{\mathtt{11}}}}{\mathtt{\,-\,}}{\frac{{\mathtt{7}}}{{\mathtt{11}}}}{\mathtt{\,\small\textbf+\,}}{\frac{{\mathtt{3}}}{{\mathtt{11}}}}{\mathtt{\,-\,}}{\frac{{\mathtt{1}}}{{\mathtt{11}}}} = {\frac{{\mathtt{4}}}{{\mathtt{11}}}} = {\mathtt{0.363\: \!636\: \!363\: \!636\: \!363\: \!6}}$$