2. Упростите выражение: а) 3n-8n-5n+2+2n; б) -3(a-2)+6(a-4)-4(3a+2); в) \frac{5}{12}(4,8p - \frac{4}{5}k) - 4,5(\frac{4}{9}p - 0,4k)

а) 3n - 8n - 5n + 2 + 2n = (3 - 8 - 5 + 2)n + 2 = -8n + 2 = 2 - 8n б) -3(a-2) + 6(a-4) - 4(3a+2) = -3a + 6 + 6a - 24 - 12a - 8 = (-3 + 6 - 12)a + (6 - 24 - 8) = -9a - 26 = -9a - 26 в) \frac{5}{12}(4,8p - \frac{4}{5}k) - 4,5(\frac{4}{9}p - 0,4k) = \frac{5}{12}⋅4,8p - \frac{5}{12}⋅\frac{4}{5}k - 4,5⋅\frac{4}{9}p + 4,5⋅0,4k = \frac{5}{1}⋅\frac{48}{120}p - \frac{1}{3}k - \frac{9}{2}⋅\frac{4}{9}p + \frac{9}{2}⋅\frac{4}{10}k = 2p - \frac{1}{3}k - 2p + \frac{18}{10}k = (2-2)p + (\frac{18}{10} - \frac{1}{3})k = 0p + (\frac{54}{30} - \frac{10}{30})k = \frac{44}{30}k = \frac{22}{15}k = \frac{22}{15}k