[tex] \\ \mathbb {}[/tex]
[tex] \\ 6 \frac{2}{5} \div 3 \frac{1}{5} - (2\frac{3}{10} + 1 \frac{3}{8} )[/tex]
[tex] \\ = \frac{32}{5} \div \frac{16}{5} - ( \frac{23}{10} + \frac{11}{8} )[/tex]
[tex] \\ = \frac{32}{5} \div \frac{16}{5} - ( \frac{92 + 55}{40} )[/tex]
[tex] \\ = \frac{32}{5} \div \frac{16}{5} - \frac{147}{40} [/tex]
[tex] \\ = \frac{32}{5} \times \frac{5}{16} - \frac{147}{40} [/tex]
[tex] \\ = 2 - \frac{147}{40} [/tex]
[tex] \\ = \frac{80 - 147}{40} [/tex]
[tex] \\ = \frac{ - 67}{40} [/tex]
[tex] \\ = - 1 \frac{27}{40} [/tex]
