Question

Помогите пожалуйста срочно ​

Answer 1

№1

$\frac{7}{13}+\frac{1}{13} =\frac{8}{13}\\\frac{3}{10} +\frac{1}{7}= \frac{21+10}{70}=\frac{31}{70} \\\frac{9}{25} +\frac{2}{5}= \frac{9+10}{25}= \frac{19}{25} \\\frac{1}{25}+ \frac{3}{35} =\frac{7+15}{175}= \frac{22}{175} \\\frac{5}{7}- \frac{2}{7}= \frac{3}{7}\\\frac{7}{9}- \frac{1}{4}= \frac{28-9}{36}= \frac{19}{36}\\\frac{7}{8}- \frac{5}{7}= \frac{49-40}{56} =\frac{9}{56}\\\frac{7}{24}- \frac{7}{36}= \frac{21-14}{72}= \frac{7}{72}$

№2

$\frac{1}{18} +(\frac{5}{18}+\frac{1}{3})=\frac{1}{18}+ \frac{5+6}{18}=\frac{12}{18} =\frac{2}{3}\\\frac{4}{15}+ \frac{7}{24}+ \frac{5}{24}+ \frac{1}{15} = \frac{4*8+7*5+5*5+1*8}{120}=\frac{100}{120}=\frac{5}{6}\\\frac{5}{7}+ \frac{4}{5}- \frac{23}{35} =\frac{5*5+4*7-23}{35} =\frac{30}{35}=\frac{6}{7}$