[tex] \frac{3a}{5b} = \frac{2}{3} [/tex]
[tex] \frac{3}{5} \times \frac{a}{b} = \frac{2}{3} [/tex]
[tex] \frac{a}{b} = \frac{2}{3} \div \frac{3}{5} [/tex]
[tex] \frac{a}{b} = \frac{2}{3} \times \frac{5}{3} [/tex]
[tex] \frac{a}{b} = \frac{2 \times 5}{3 \times 3} [/tex]
[tex] \frac{a}{b} = \frac{10}{9} [/tex]
[tex]{(\frac{a}{b})}^{-1}=\frac{b}{a}=\frac{9}{10}[/tex]
