Памогите срочно номер 623

1)
$\frac{ \frac{5}{6} - \frac{1}{3} }{ \frac{1}{3} - \frac{5}{6} } = - \frac{ \frac{5}{6} - \frac{1}{3} }{ \frac{5}{6}- \frac{1}{3} } = - 1$
2)
$\frac{ \frac{1}{2} - \frac{2}{3} }{ \frac{2}{3} - \frac{1}{2} } = - \frac{ \frac{1}{2} - \frac{2}{3} }{ \frac{1}{2} - \frac{2}{3} } = - 1$
3)
$\frac{1.7 - 2}{2 - 1.7} = - \frac{1.7 - 2}{1.7 - 2} = - 1$
4)
$\frac{0.9 - 3}{3 - 0.9} = - \frac{0.9 - 3}{0.9 - 3} = - 1$