Problem: if 8 a = 9 b and ab ≠ 0 , what is the ratio of a / 9 to b / 8 ?
Rationale: "if ab ≠ 0 then a and b has two integer sets of pair if a = 9 then b = 8 and if a = - 9 then b = - 8 also in fraction if a = 1 / 8 then b = 1 / 9 any of the pair we check the ratio 8 a / 9 b = 1 answer : c"
annotated_formula: divide(multiply(8, 9), multiply(9, 8))