3. Вычислите значение выражения наиболее удобным спосо- бом: 1) 3\frac{1}{11} · 4\frac{2}{5} + 1\frac{5}{11}·4\frac{2}{5};

1) 3$$\frac{1}{11}$$ $$\cdot$$ 4$$\frac{2}{5}$$ + 1$$\frac{5}{11}$$\cdot$$4$$\frac{2}{5}$$ = 4$$\frac{2}{5}$$ $$\cdot$$ (3$$\frac{1}{11}$$ + 1$$\frac{5}{11}$$) = 4$$\frac{2}{5}$$ $$\cdot$$ (3 + 1 + $$\frac{1}{11}$$ + $$\frac{5}{11}$$) = 4$$\frac{2}{5}$$ $$\cdot$$ (4 + $$\frac{1+5}{11}$$) = 4$$\frac{2}{5}$$ $$\cdot$$ (4 + $$\frac{6}{11}$$) = $$\frac{4 \cdot 5 + 2}{5}$$\cdot$$\frac{4 \cdot 11 + 6}{11}$$ = $$\frac{20 + 2}{5}$$\cdot$$\frac{44 + 6}{11}$$ = $$\frac{22}{5}$$\cdot$$\frac{50}{11}$$ = $$\frac{2 \cdot 11}{5}$$\cdot$$\frac{5 \cdot 10}{11}$$ = 2$$\cdot$$10 = 20

Ответ: 20