Question

Помогите решить!!! Действия подробно

Answer 1

$1) 4 - 1 \frac{9}{10} = 3 \frac{10}{10} - 1 \frac{9}{10} = 2 \frac{1}{10} \\\\ 2) \frac{9}{25} : 2\frac{1}{10}= \frac{9}{25}* \frac{10}{21}= \frac{6}{35}\\\\ 3) \frac{3}{10} - \frac{6}{35} = \frac{21-12}{70} = \frac{9}{70} \\\\ 4)\frac{9}{70}+\frac{4}{7}= \frac{9+40}{70} = \frac{49}{70} = \frac{7}{10}$

Answer 2

$\frac{3}{10} - \frac{9}{25} \div ( \frac{4}{1} - \frac{19}{10} ) + \frac{4}{7} = \frac{3}{10} - \frac{9}{25} \div ( \frac{4 \times 10 - 19}{10} ) + \frac{4}{7} = \frac{3}{10} - \frac{9}{25} \times \frac{10}{21} + \frac{4}{7} = \frac{3}{10} - \frac{3 \times 2}{5 \times 7} + \frac{4}{7} = \frac{3}{10} - \frac{6}{35} + \frac{4}{7} = \frac{3 \times 35 - 6 \times 10 + 4 \times 50}{350} = \frac{105 - 60 + 200}{350} = \frac{245}{350} = \frac{7}{10} = 0.7$