Ответ:

\(-5\frac{1}{16}+1\frac18=-\frac{81}{16}+\frac{18}{16}=-\frac{63}{16}\).

\(-\frac56-\frac34=-\frac{10}{12}-\frac{9}{12}=-\frac{19}{12}\).

\(\left(-\frac{63}{16}\right)\left(-\frac{19}{12}\right)=\frac{399}{64}=6\frac{15}{64}\).

Ответ: \(\frac{399}{64}\).