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

$$\frac{1}{4}y = \frac{1}{4} + \frac{1}{4}$$

$$\frac{1}{4}y = \frac{2}{4}$$

$$y = \frac{2}{4} : \frac{1}{4}$$

$$y = \frac{2}{4} \cdot \frac{4}{1}$$

$$y = \frac{2 \cdot 4}{4 \cdot 1}$$

$$y = \frac{8}{4}$$

$$y = 2$$

Ответ: $$y=2$$