Решение:
$$\frac{9}{4}$$\cdot$$0,77 - $$\frac{9}{4}$$\cdot$$2,83 = $$\frac{9}{4}$$ (0,77 - 2,83) = $$\frac{9}{4}$$ $$\cdot$$ (-2,06) = -$$\frac{9}{4}$$\cdot$$2,06 = -9$$\cdot$$\frac{2,06}{4}$$ = -9$$\cdot$$0,515 = -4,635
Ответ: -4,635