\(a\frac25+x=7--1,62=\frac25+x=8,62=x=8,62-\frac25=x=8,22,\) \(\frac{23}{5}-x=\) \(\frac{-1}{5}+\frac12=\frac{23}{5}-x=\frac{3}{10}=x=\frac{23}{5}-\frac{3}{10}=\frac{43}{10},\frac{-4}{7}-x=\frac35-2x=2x-x=\frac{-4}{7}-\frac35=x=\frac{41}{35}\) \(\frac57-\frac{1}{13}+0.25=\frac72-x=\frac{323}{364}=\frac72-x=\frac{1597}{364}\)

\(a\frac25+x=7--1,62=\frac25+x=8,62=x=8,62-\frac25=x=8,22,\) \(\frac{23}{5}-x=\) \(\frac{-1}{5}+\frac12=\frac{23}{5}-x=\frac{3}{10}=x=\frac{23}{5}-\frac{3}{10}=\frac{43}{10},\frac{-4}{7}-x=\frac35-2x=2x-x=\frac{-4}{7}-\frac35=x=\frac{41}{35}\) \(\frac57-\frac{1}{13}+0.25=\frac72-x=\frac{323}{364}=\frac72-x=\frac{1597}{364}\)

\(a\frac25+x=7--1,62=\frac25+x=8,62=x=8,62-\frac25=x=8,22,\) \(\frac{23}{5}-x=\) \(\frac{-1}{5}+\frac12=\frac{23}{5}-x=\frac{3}{10}=x=\frac{23}{5}-\frac{3}{10}=\frac{43}{10},\frac{-4}{7}-x=\frac35-2x=2x-x=\frac{-4}{7}-\frac35=x=\frac{41}{35}\) \(\frac57-\frac{1}{13}+0.25=\frac72-x=\frac{323}{364}=\frac72-x=\frac{1597}{364}\)

\(a\frac25+x=7--1,62=\frac25+x=8,62=x=8,62-\frac25=x=8,22,\) \(\frac{23}{5}-x=\) \(\frac{-1}{5}+\frac12=\frac{23}{5}-x=\frac{3}{10}=x=\frac{23}{5}-\frac{3}{10}=\frac{43}{10},\frac{-4}{7}-x=\frac35-2x=2x-x=\frac{-4}{7}-\frac35=x=\frac{41}{35}\) \(\frac57-\frac{1}{13}+0.25=\frac72-x=\frac{323}{364}=\frac72-x=\frac{1597}{364}\)

\(a\frac25+x=7--1,62=\frac25+x=8,62=x=8,62-\frac25=x=8,22,\) \(\frac{23}{5}-x=\) \(\frac{-1}{5}+\frac12=\frac{23}{5}-x=\frac{3}{10}=x=\frac{23}{5}-\frac{3}{10}=\frac{43}{10},\frac{-4}{7}-x=\frac35-2x=2x-x=\frac{-4}{7}-\frac35=x=\frac{41}{35}\) \(\frac57-\frac{1}{13}+0.25=\frac72-x=\frac{323}{364}=\frac72-x=\frac{1597}{364}\)

\(a\frac25+x=7--1,62=\frac25+x=8,62=x=8,62-\frac25=x=8,22,\) \(\frac{23}{5}-x=\) \(\frac{-1}{5}+\frac12=\frac{23}{5}-x=\frac{3}{10}=x=\frac{23}{5}-\frac{3}{10}=\frac{43}{10},\frac{-4}{7}-x=\frac35-2x=2x-x=\frac{-4}{7}-\frac35=x=\frac{41}{35}\) \(\frac57-\frac{1}{13}+0.25=\frac72-x=\frac{323}{364}=\frac72-x=\frac{1597}{364}\)

\(a\frac25+x=7--1,62=\frac25+x=8,62=x=8,62-\frac25=x=8,22,\) \(\frac{23}{5}-x=\) \(\frac{-1}{5}+\frac12=\frac{23}{5}-x=\frac{3}{10}=x=\frac{23}{5}-\frac{3}{10}=\frac{43}{10},\frac{-4}{7}-x=\frac35-2x=2x-x=\frac{-4}{7}-\frac35=x=\frac{41}{35}\) \(\frac57-\frac{1}{13}+0.25=\frac72-x=\frac{323}{364}=\frac72-x=\frac{1597}{364}\)

\(a\frac25+x=7--1,62=\frac25+x=8,62=x=8,62-\frac25=x=8,22,\) \(\frac{23}{5}-x=\) \(\frac{-1}{5}+\frac12=\frac{23}{5}-x=\frac{3}{10}=x=\frac{23}{5}-\frac{3}{10}=\frac{43}{10},\frac{-4}{7}-x=\frac35-2x=2x-x=\frac{-4}{7}-\frac35=x=\frac{41}{35}\) \(\frac57-\frac{1}{13}+0.25=\frac72-x=\frac{323}{364}=\frac72-x=\frac{1597}{364}\)

\(a\frac25+x=7--1,62=\frac25+x=8,62=x=8,62-\frac25=x=8,22,\) \(\frac{23}{5}-x=\) \(\frac{-1}{5}+\frac12=\frac{23}{5}-x=\frac{3}{10}=x=\frac{23}{5}-\frac{3}{10}=\frac{43}{10},\frac{-4}{7}-x=\frac35-2x=2x-x=\frac{-4}{7}-\frac35=x=\frac{41}{35}\) \(\frac57-\frac{1}{13}+0.25=\frac72-x=\frac{323}{364}=\frac72-x=\frac{1597}{364}\)

\(\left(\frac27\cdot\frac14-\frac13\cdot\frac27\right):\left(\frac27\cdot\frac39-\frac27\cdot\frac25\right)=\frac27\left(\frac14-\frac13\right):\frac27\left(\frac39-\frac25\right)=\frac54,B\frac34\frac{\left(\frac15-\frac27-\frac13+\frac27\right)}{\frac15\left(\frac27+\frac13\right)-\frac13\left(\frac27+\frac13\right)}=\frac{\frac34\left(\frac15-\frac13\right)}{\left(\frac15-\frac13\right)\left(\frac27+\frac13\right)}=\frac{63}{52}\)