Step-by-step explanation:
[tex] \sin( \alpha - \beta ) = \sin( \alpha ) \cos( \beta ) - \cos( \alpha ) \sin( \beta ) [/tex]
Using the Pythagorean theorem,
[tex] \cos( \alpha ) = \frac{4}{5} [/tex]
[tex] \sin( \beta ) = \frac{8}{10} [/tex]
[tex] \sin( \alpha - \beta ) = ( \frac{3}{5} )( \frac{3}{5} ) - ( \frac{4}{5} )( \frac{4}{5} )[/tex]
[tex] \frac{9}{25} - \frac{16}{25} = \frac{ - 7}{25} [/tex]