2.464 Решите уравнение: a) (z – 6) * 3/7 = 3; б) 5 1/4 y – 5 1/4 = 5 1/4.

Решение:

1. a) $$(z - 6) \cdot \frac{3}{7} = 3$$ $$z - 6 = 3 : \frac{3}{7}$$ $$z - 6 = 3 \cdot \frac{7}{3}$$ $$z - 6 = 7$$ $$z = 7 + 6$$ $$z = 13$$
2. б) $$5 \frac{1}{4}y - 5 \frac{1}{4} = 5 \frac{1}{4}$$ $$\frac{21}{4}y - \frac{21}{4} = \frac{21}{4}$$ $$\frac{21}{4}y = \frac{21}{4} + \frac{21}{4}$$ $$\frac{21}{4}y = \frac{42}{4}$$ $$y = \frac{42}{4} : \frac{21}{4}$$ $$y = \frac{42}{4} \cdot \frac{4}{21}$$ $$y = 2$$

Ответ: а) $$z = 13$$; б) $$y = 2$$