Решите уравнение: 1) 7: 8 = x : 96 2) y: $$1\frac{5}{31}$$ = $$7\frac{3}{4}$$: $$\frac{1}{3}$$ 3) $$\frac{a}{0.6} = \frac{25}{3}$$ 4) $$\frac{2+x}{5} = \frac{4}{9}$$

7 : 8 = x : 96

$$x = \frac{7 \cdot 96}{8} = 7 \cdot 12 = 84$$

Ответ: x = 84

$$y : 1\frac{5}{31} = 7\frac{3}{4} : \frac{1}{3}$$

$$y : \frac{36}{31} = \frac{31}{4} : \frac{1}{3}$$

$$y : \frac{36}{31} = \frac{31}{4} \cdot 3$$

$$y = \frac{31 \cdot 3 \cdot 36}{4 \cdot 31} = \frac{3 \cdot 36}{4} = 3 \cdot 9 = 27$$

Ответ: y = 27

$$\frac{a}{0.6} = \frac{25}{3}$$

$$a = \frac{25 \cdot 0.6}{3} = \frac{25 \cdot 6}{3 \cdot 10} = \frac{25 \cdot 2}{10} = \frac{50}{10} = 5$$

Ответ: a = 5

$$\frac{2+x}{5} = \frac{4}{9}$$

$$2 + x = \frac{4 \cdot 5}{9} = \frac{20}{9}$$

$$x = \frac{20}{9} - 2 = \frac{20 - 18}{9} = \frac{2}{9}$$

Ответ: $$x = \frac{2}{9}$$