Question

Помогите срочно!!Вот этот пример

Answer 1

$1) 4 - 1 \frac{9}{10} = 3 \frac{10}{10} - 1 \frac{9}{10} = 2 \frac{1}{10} \\\\ 2) \frac{9}{20} : 2\frac{1}{10}= \frac{9}{20}* \frac{10}{21}= \frac{3}{14}\\\\ 3) \frac{3}{10} - \frac{3}{14} = \frac{21-15}{70} = \frac{6}{70}= \frac{3}{35} \\\\ 4)\frac{3}{35}+\frac{4}{7}= \frac{3+20}{35} = \frac{23}{35}$