[tex]-\frac{157}{20}=-\frac{140+17}{20}=-\left(\frac{140}{20}+\frac{17}{20}\right)=-7\frac{17}{20}\\\\-7\frac{17}{20}\to\ divide\ 17\ by\ 20\to\boxed{-7\frac{17}{20}=-7.85}\\\\other\ way\\\\-7\frac{17}{20}=-7\frac{17\cdot5}{20\cdot5}=-7\frac{85}{100}=\boxed{-7.85}[/tex]