№3. Раскройте скобки и решите уравнение: 1) $$-\frac{5}{7}(m - 1) = \frac{11}{14}$$ 2) $$-1,3 + (x - 4,8) = -7,1$$

Решение:

1) $$-\frac{5}{7}(m - 1) = \frac{11}{14}$$
$$-\frac{5}{7}m + \frac{5}{7} = \frac{11}{14}$$
$$-\frac{5}{7}m = \frac{11}{14} - \frac{5}{7}$$
$$-\frac{5}{7}m = \frac{11}{14} - \frac{10}{14}$$
$$-\frac{5}{7}m = \frac{1}{14}$$
$$m = \frac{1}{14} : (-\frac{5}{7})$$
$$m = \frac{1}{14} \cdot (-\frac{7}{5})$$
$$m = -\frac{1}{10} = -0,1$$

2) $$-1,3 + (x - 4,8) = -7,1$$
$$-1,3 + x - 4,8 = -7,1$$
$$x - 6,1 = -7,1$$
$$x = -7,1 + 6,1$$
$$x = -1$$