Question

СРОЧНО!!!! Пожалуйста

Answer 1

Ответ:

$\frac{4}{7}(2.1m-2.8n)-\frac{4}{5}(1\frac{1}{2}n-1\frac{1}{4}m) = 4*0.3m-4*0.4n- \frac{4}{5}(\frac{3}{2}n-\frac{5}{4}m) =1.2m-1.6n-\frac{12}{10}n+m = 2.2m-1.6n-1,2n = 2.2m-2.8n$