Problem: a and b together can do a work in 7 days . if a alone can do it in 56 days . in how many days can b alone do it ?
Rationale: "b 8 1 / 7 â € “ 1 / 56 = 1 / 8 = > 8"
annotated_formula: add(inverse(subtract(divide(const_1, 7), divide(const_1, 56))), divide(const_2, add(const_2, const_3)))