Question

помогите пж (7 класс)​

Answer 1

Ответ:

$=2 \times {3}^{20} - 5 \times { 3}^{19} = {3}^{19} (2 \times 3 - 5) = {3}^{19} \\ {9}^{9} = {3}^{18 } \\ \frac{ {3}^{19} }{ {3}^{18} } = 3$