3. Решим уравнения:
а) $$\frac{4}{7}y = 4,2$$
$$y=4,2:\frac{4}{7}=4,2\cdot\frac{7}{4}=\frac{42}{10}\cdot\frac{7}{4}=\frac{21}{5}\cdot\frac{7}{4}=\frac{147}{20}=7,35$$
б) $$x:6=5\frac{7}{24}$$
$$x=5\frac{7}{24}\cdot6=\frac{5\cdot24+7}{24}\cdot6=\frac{127}{24}\cdot6=\frac{127}{4}=\frac{127}{4}=31,75$$
Ответ: a) 7,35, б) 31,75