Ответ:

[tex]( - 5 \frac{3}{5} ) \times ( - 1 \frac{4}{21} ) = ( - \frac{28}{5} ) \times ( - \frac{25}{21} ) =( - \frac{4}{1} )\times ( - \frac{5}{3} ) = \frac{20}{3} = 6 \frac{2}{3} [/tex]