Ответ:

[tex] - 18 \times \frac{13}{80} [/tex]

[tex] - 11 \frac{1}{16} + ( - 7 \frac{1}{10} ) = - 11 \frac{1}{16} - 7 \frac{1}{10} = - 11 \frac{5}{80} - 7 \frac{8}{80} = - 18 \frac{13}{80} [/tex]

- 18 13 / 80