b)

① →: $R_{Bx} = 0$ (1)

$\varphi$ : $R_{Ay} + R_{By} - mg = 0$ (2)

$\widehat{B'}$ : $R_{Ay}b - mgc = 0$ (3)

② →: $-R_{Bx} - R_{Ox} = 0$ (4)

$\varphi$ : $-R_{By} - R_{Oy} + R_{Cy} = 0$ (5)

$\widehat{B'}$ : $R_{Cy}b + R_{Ox}\frac{h}{2} - R_{Oy}\frac{b}{2} = 0$ (6)

③ →: $R_{Ox} + R_{Ox} + F\cos \beta = 0$ (7)

$\varphi$ : $R_{Oy} - R_{Ay} + R_{Oy} + F\sin \beta = 0$ (8)

$\widehat{O'}$ : $-R_{Ay}b + R_{Ox}\frac{h}{2} + R_{Oy}\frac{b}{2} + F_{ox}\cos \beta \sin \alpha + F_{ox}\sin \beta \cos \alpha = 0$ (9)