Find $\displaystyle {\sin{{\left(\alpha-\beta\right)}}}$ exactly, given $\displaystyle {\sin{\alpha}}=\frac{{1}}{{9}}$  and $\displaystyle {\sin{\beta}}=\frac{{4}}{{7}}$ where $\displaystyle \alpha$ terminates in quadrant II and $\displaystyle \beta$ terminates in quadrant I. Be sure to reduce your final result completely.