2. Упростите выражение: a) 3n8n5n+2+2n; б)3(a2)+6(a4)4(3a + 2); в)(4,8-4-4,5-0,4k).

а)

3n - 8n - 5n + 2 + 2n =

(3n - 8n - 5n + 2n) + 2 =

-8n + 2

б)

-3(a - 2) + 6(a - 4) - 4(3a + 2) =

-3a + 6 + 6a - 24 - 12a - 8 =

(-3a + 6a - 12a) + (6 - 24 - 8) =

-9a - 26

в)

\[\frac{5}{12}(4,8p - 4k) - 4,5(\frac{4}{9}p - 0,4k) = \]

\[\frac{5}{12} \cdot 4,8p - \frac{5}{12} \cdot 4k - 4,5 \cdot \frac{4}{9}p + 4,5 \cdot 0,4k = \]

\[2p - \frac{5}{3}k - 2p + 1,8k = \]

\[-\frac{5}{3}k + 1,8k = \]

\[-\frac{5}{3}k + \frac{9}{5}k = \]

\[-\frac{25}{15}k + \frac{27}{15}k = \]

\[\frac{2}{15}k\]