`9.`

$\sum M_B = 0$

$F \cdot AB = T_x \cdot AB$

$F \cdot AB = (T \cdot \sin \alpha) \cdot AB$

`T = \frac{F}{\sin \alpha} = \frac{100}{\sin 30^\circ}`

`T = \frac{100}{0,5} = 200 \text{ N}`

`R_x + F - T \cdot \sin \alpha = 0`

$R_x = T \cdot \sin 30^\circ - F = 200 \cdot 0,5 - 100 = 0 \text{ N}$

$R_y - T \cdot \cos \alpha = 0$

`R_y = 200 \cdot \cos 30^\circ = 200 \cdot \frac{\sqrt{3}}{2} \approx 173,2 \text{ N}`