3. Решите уравнение: а) x - 3,22 = -8,19; б) $$2\frac{8}{15}$$ + y = -$$1\frac{7}{10}$$.

Решение: а) x - 3,22 = -8,19 x = -8,19 + 3,22 x = - (8,19 - 3,22) x = -4,97 б) $$2\frac{8}{15}$$ + y = -$$1\frac{7}{10}$$ $$\frac{2 * 15 + 8}{15}$$ + y = -$$\frac{1 * 10 + 7}{10}$$ $$\frac{38}{15}$$ + y = -$$\frac{17}{10}$$ y = -$$\frac{17}{10}$$ - $$\frac{38}{15}$$ y = -$$\frac{17 * 3}{10 * 3}$$ - $$\frac{38 * 2}{15 * 2}$$ y = -$$\frac{51}{30}$$ - $$\frac{76}{30}$$ y = -$$\frac{51 + 76}{30}$$ y = -$$\frac{127}{30}$$ y = -$$4\frac{7}{30}$$ Ответ: a) x = -4,97 б) y = -$$4\frac{7}{30}$$