5.124 Решите уравнение: a) -5(-y + 9) = y + 10; 6) m - 17 = (m + 4)(-9); в) 17 - 4(m + 11) = 43;

Решим уравнения:

1. a) $$-5(-y + 9) = y + 10$$ $$\Leftrightarrow$$ $$5y - 45 = y + 10$$ $$\Leftrightarrow$$ $$5y - y = 10 + 45$$ $$\Leftrightarrow$$ $$4y = 55$$ $$\Leftrightarrow$$ $$y = \frac{55}{4}$$ $$\Leftrightarrow$$ $$y = 13,75$$
2. б) $$m - 17 = (m + 4)(-9)$$ $$\Leftrightarrow$$ $$m - 17 = -9m - 36$$ $$\Leftrightarrow$$ $$m + 9m = -36 + 17$$ $$\Leftrightarrow$$ $$10m = -19$$ $$\Leftrightarrow$$ $$m = -1,9$$
3. в) $$17 - 4(m + 11) = 43$$ $$\Leftrightarrow$$ $$17 - 4m - 44 = 43$$ $$\Leftrightarrow$$ $$-4m = 43 - 17 + 44$$ $$\Leftrightarrow$$ $$-4m = 70$$ $$\Leftrightarrow$$ $$m = -17,5$$

Ответ: a) $$y = 13,75$$, б) $$m = -1,9$$, в) $$m = -17,5$$