4 Решите уравнения: a) 9$$\frac{1}{2}$$x = 3$$\frac{1}{6}$$\cdot$$12; б) (1$$\frac{5}{7}$$ + 3$$\frac{9}{14}$$) - x = 4$$\frac{3}{7}$$

a) 9$$\frac{1}{2}$$x = 3$$\frac{1}{6}$$\cdot$$12

$$\frac{9 \cdot 2 + 1}{2}$$x = $$\frac{3 \cdot 6 + 1}{6}$$\cdot$$12

$$\frac{19}{2}$$x = $$\frac{19}{6}$$\cdot$$12

$$\frac{19}{2}$$x = 19$$\cdot$$2

$$\frac{19}{2}$$x = 38

x = 38 : $$\frac{19}{2}$$

x = 38$$\cdot$$\frac{2}{19}$$

x = 2$$\cdot$$2

x = 4

Ответ: 4

б) (1$$\frac{5}{7}$$ + 3$$\frac{9}{14}$$) - x = 4$$\frac{3}{7}$$

($$\frac{1 \cdot 7 + 5}{7}$$ + $$\frac{3 \cdot 14 + 9}{14}$$) - x = $$\frac{4 \cdot 7 + 3}{7}$$

($$\frac{12}{7}$$ + $$\frac{51}{14}$$) - x = $$\frac{31}{7}$$

($$\frac{12 \cdot 2 + 51}{14}$$) - x = $$\frac{31}{7}$$

($$\frac{24 + 51}{14}$$) - x = $$\frac{31}{7}$$

$$\frac{75}{14}$$ - x = $$\frac{31}{7}$$

x = $$\frac{75}{14}$$ - $$\frac{31}{7}$$

x = $$\frac{75 - 31 \cdot 2}{14}$$

x = $$\frac{75 - 62}{14}$$

x = $$\frac{13}{14}$$

Ответ: $$\frac{13}{14}$$