Решение:
-1$$\frac{7}{8}$$ = -$$\frac{1 * 8 + 7}{8}$$ = -$$\frac{15}{8}$$
1$$\frac{1}{3}$$ = $$\frac{1 * 3 + 1}{3}$$ = $$\frac{4}{3}$$
-$$\frac{15}{8}$$ * $$\frac{4}{3}$$ = -$$\frac{15 * 4}{8 * 3}$$ = -$$\frac{60}{24}$$ = -$$\frac{5}{2}$$ = -2,5
Ответ: -2,5