5. Упрости выражение: а) -8(x - 3) + 4(x - 2) – 2(3x+1); б) $$\frac{5}{9}(3,6a-\frac{3}{5}d)-3,5(\frac{4}{7}a-0,2d)$$.

а) -8(x - 3) + 4(x - 2) - 2(3x + 1) = -8x + 24 + 4x - 8 - 6x - 2 = (-8 + 4 - 6)x + (24 - 8 - 2) = -10x + 14 = -10x + 14 б) $$\frac{5}{9}(3,6a-\frac{3}{5}d)-3,5(\frac{4}{7}a-0,2d) = \frac{5}{9} * 3,6a - \frac{5}{9} * \frac{3}{5}d - 3,5 * \frac{4}{7}a + 3,5 * 0,2d = 2a - \frac{1}{3}d - 2a + 0,7d = (2 - 2)a + (0,7 - \frac{1}{3})d = 0a + (\frac{7}{10} - \frac{1}{3})d = (\frac{21}{30} - \frac{10}{30})d = \frac{11}{30}d$$ Ответ: $$\frac{11}{30}d$$