Problem: what is the least possible value of x ^ 2 - 15 where x is a positive number .
Rationale: if x is a positive integer , the lowest value would be x = 1 , because 0 is not included in the natural numbers . that ' s a technicality the gmat would not expect students to know . if x = 1 , then the expression equals - 14 . answer = ( b ) .
annotated_formula: subtract(subtract(const_1, const_1), 15)