Coroana??
[tex] \frac{13}{14} - ( \frac{5}{7} - \frac{3}{10} ) = \frac{13}{14} - ( \frac{10 \times 5}{70} - \frac{7 \times 3}{70} )[/tex]
[tex] \frac{13}{14} - ( \frac{50 - 21}{70} ) = \frac{13}{14} - \frac{29}{70} = \frac{13 \times 5}{70} - \frac{29}{70} [/tex]
[tex] = 65 - 29 = 36[/tex]