[tex]\displaystyle (\frac{2}{3}-1,2)-(1,8+\frac{2}{3})=(\frac{2}{3}-\frac{6}{5})-(\frac{9}{5}+\frac{2}{3})=(-\frac{8}{15})-\frac{37}{15}=-\frac{8}{15}-\frac{37}{15}=-3[/tex]