Question

помогите пж очень надо дам 20 баллов

Answer 1

$dfrac{9}{10}+dfrac{4}{9}:Big(11-10dfrac{11}{21}Big)-1dfrac{2}{3}=dfrac{9}{10}+dfrac{4}{9}:dfrac{10}{21}-dfrac{5}{3}=dfrac{9}{10}+dfrac{4}{9}cdot dfrac{21}{10}-dfrac{5}{3}=\\\=dfrac{9}{10}+dfrac{2cdot 7}{3cdot 5}-dfrac{5}{3}=dfrac{9}{10}+dfrac{14}{15}-dfrac{5}{3}=dfrac{27+28-50}{30}=dfrac{5}{30}=dfrac{1}{6}$