Problem: if a * b = 2 a - 3 b + ab , then 3 * 5 + 5 * 3 is equal to :
Rationale: "explanation : 3 * 5 + 5 * 3 = ( 2 * 3 - 3 * 5 + 3 * 5 ) + ( 2 * 5 - 3 * 3 + 5 * 3 ) = ( 6 + 10 - 9 + 15 ) = 22 . answer : a ) 22"
annotated_formula: add(multiply(2, 3), multiply(3, 5))