Ответ:
\[2\frac13=\frac73,\quad \frac58-\frac83=\frac{15-64}{24}=-\frac{49}{24},\quad 1\frac37=\frac{10}{7}.\]
\[\frac73:\left(-\frac{49}{24}\right)+2\cdot\frac{10}{7}=-\frac87+\frac{20}{7}=\frac{12}{7}.\]
Ответ: \(\frac{12}{7}=1\frac57\).
\[2\frac13=\frac73,\quad \frac58-\frac83=\frac{15-64}{24}=-\frac{49}{24},\quad 1\frac37=\frac{10}{7}.\]
\[\frac73:\left(-\frac{49}{24}\right)+2\cdot\frac{10}{7}=-\frac87+\frac{20}{7}=\frac{12}{7}.\]
Ответ: \(\frac{12}{7}=1\frac57\).