8) 1/6 t - 18k² - 10k - 2/5 tk - 9/3 k - 1/8 k =

Преобразуем выражение:

$$ \frac{1}{6}t - 18k^2 - 10k - \frac{2}{5}tk - \frac{9}{3}k - \frac{1}{8}k = \frac{1}{6}t - 18k^2 - 10k - \frac{2}{5}tk - 3k - \frac{1}{8}k $$

Приведем подобные члены:

$$ \frac{1}{6}t - 18k^2 - 10k - 3k - \frac{1}{8}k - \frac{2}{5}tk = \frac{1}{6}t - 18k^2 + (-10 - 3 - \frac{1}{8})k - \frac{2}{5}tk $$ $$ \frac{1}{6}t - 18k^2 + (-13 - \frac{1}{8})k - \frac{2}{5}tk = \frac{1}{6}t - 18k^2 - \frac{104 + 1}{8}k - \frac{2}{5}tk = \frac{1}{6}t - 18k^2 - \frac{105}{8}k - \frac{2}{5}tk $$

Ответ: 1/6 t-18k²-105/8 k-2/5 tk