PROBLEM:1.236

 A force F =Aj is applied to a point whose radius vector r1 = ai, while a force F₂ = Bi is applied to the point whose radius vector r₂ = bj. Both radius vectors are determined relative to the origin of coordinates O, i and j are the unit vectors of the x and y axes, a, b, A, B are constants. Find the arm L of the resultant force relative to the point 0.