Решение уравнений

a)

$$11,4b - (2,7b + 3,2b) + 2,35 = 6,2$$

$$11,4b - 5,9b + 2,35 = 6,2$$

$$5,5b = 6,2 - 2,35$$

$$5,5b = 3,85$$

$$b = \frac{3,85}{5,5}$$

$$b = 0,7$$

Ответ: $$b = 0,7$$.

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б)

$$15d - (12,1d - 0,7d) + 5,6 = 20$$

$$15d - 11,4d + 5,6 = 20$$

$$3,6d = 20 - 5,6$$

$$3,6d = 14,4$$

$$d = \frac{14,4}{3,6}$$

$$d = 4$$

Ответ: $$d = 4$$.

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в)

$$3x + \frac{1}{6} - (3\frac{1}{2}x - 1\frac{1}{4}x) = 4\frac{2}{3}$$

$$3x + \frac{1}{6} - (\frac{7}{2}x - \frac{5}{4}x) = \frac{14}{3}$$

$$3x + \frac{1}{6} - (\frac{14}{4}x - \frac{5}{4}x) = \frac{14}{3}$$

$$3x + \frac{1}{6} - \frac{9}{4}x = \frac{14}{3}$$

$$3x - \frac{9}{4}x = \frac{14}{3} - \frac{1}{6}$$

$$\frac{12}{4}x - \frac{9}{4}x = \frac{28}{6} - \frac{1}{6}$$

$$\frac{3}{4}x = \frac{27}{6}$$

$$\frac{3}{4}x = \frac{9}{2}$$

$$x = \frac{9}{2} : \frac{3}{4}$$

$$x = \frac{9}{2} * \frac{4}{3}$$

$$x = \frac{36}{6}$$

$$x = 6$$

Ответ: $$x = 6$$.