5.544 Решите уравнение: а) $$(z-6) \cdot \frac{3}{7} = 3$$; б) $$\frac{1}{4}y - \frac{1}{4} = \frac{1}{4}$$.

а) $$(z - 6) \cdot \frac{3}{7} = 3$$ $$z - 6 = 3 : \frac{3}{7}$$ $$z - 6 = 3 \cdot \frac{7}{3}$$ $$z - 6 = \frac{3 \cdot 7}{3}$$ $$z - 6 = 7$$ $$z = 7 + 6$$ $$z = 13$$

Ответ: z = 13

б) $$\frac{1}{4}y - \frac{1}{4} = \frac{1}{4}$$ $$\frac{1}{4}y = \frac{1}{4} + \frac{1}{4}$$ $$\frac{1}{4}y = \frac{2}{4}$$ $$y = \frac{2}{4} : \frac{1}{4}$$ $$y = \frac{2}{4} \cdot \frac{4}{1}$$ $$y = \frac{2 \cdot 4}{4 \cdot 1}$$ $$y = 2$$

Ответ: y = 2