How can I figure out

$3-85.$ The belt passing over the pulley is subjected to forces $F_1$ and $F_2,$ each having a magnitude of $40N.F_1$ acts in the $-k$ direction. Replace these forces by an equivalent force and couple moment at point $A.$ Express the result in Cartesian vector form. Set $=0$ so that $F_2$ acts in the $-j$ direction.

$3-86.$ The belt passing over the pulley is subjected to two forces $F_1$ and $F_2,$ each having a magnitude of $40N.F_1$ acts in the $-k$ direction. Replace these forces by an equivalent force and couple moment at point $A.$ Express the result in Cartesian vector form. Take $=45.$

Probs. $3-\frac{85}{86}$ Please solve $3-86$