6^2-4^2-8^2 over -2*4*8

$${\frac{\left({{\mathtt{6}}}^{{\mathtt{2}}}{\mathtt{\,-\,}}{{\mathtt{4}}}^{{\mathtt{2}}}{\mathtt{\,-\,}}{{\mathtt{8}}}^{{\mathtt{2}}}\right)}{{\mathtt{\,-\,}}\left({\mathtt{2}}{\mathtt{\,\times\,}}{\mathtt{4}}{\mathtt{\,\times\,}}{\mathtt{8}}\right)}} = {\frac{{\mathtt{11}}}{{\mathtt{16}}}} = {\mathtt{0.687\: \!5}}$$

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