1. Выполним действия:
a) 4 - 1$$\frac{5}{6}$$ = 4 - $$\frac{1 \cdot 6 + 5}{6}$$ = 4 - $$\frac{11}{6}$$ = 4 - 1$$\frac{5}{6}$$ = 3$$\frac{6}{6}$$ - 1$$\frac{5}{6}$$ = 2$$\frac{1}{6}$$
б) 3$$\frac{1}{4}$$ - 2$$\frac{3}{4}$$ = $$\frac{3 \cdot 4 + 1}{4}$$ - $$\frac{2 \cdot 4 + 3}{4}$$ = $$\frac{13}{4}$$ - $$\frac{11}{4}$$ = $$\frac{2}{4}$$ = $$\frac{1}{2}$$
Ответ: a) 2$$\frac{1}{6}$$; б) $$\frac{1}{2}$$