[tex](1 - \frac{1}{5} ) \times \frac{3}{5} - \frac{1}{5} \\ [/tex]
[tex]( \frac{1}{5} + 6) \div \frac{3}{5}1 - 1 [/tex]
[tex](1 - \frac{1}{2} ^{2} + 1[/tex]
​