Уменьшим целую часть чисел 3$$\frac{4}{9}$$, 9$$\frac{21}{22}$$, 4$$\frac{9}{10}$$ на единицу, запишем в виде неправильной дроби.
3$$\frac{4}{9}$$ - 1 = 2$$\frac{4}{9}$$ = $$\frac{2 \cdot 9 + 4}{9}$$ = $$\frac{18 + 4}{9}$$ = $$\frac{22}{9}$$
9$$\frac{21}{22}$$ - 1 = 8$$\frac{21}{22}$$ = $$\frac{8 \cdot 22 + 21}{22}$$ = $$\frac{176 + 21}{22}$$ = $$\frac{197}{22}$$
4$$\frac{9}{10}$$ - 1 = 3$$\frac{9}{10}$$ = $$\frac{3 \cdot 10 + 9}{10}$$ = $$\frac{30 + 9}{10}$$ = $$\frac{39}{10}$$
Ответ: $$\frac{22}{9}$$; $$\frac{197}{22}$$; $$\frac{39}{10}$$