a number is doubled and 9 is added . if the resultant is trebled , it becomes 57 . what is that number ?
"let the number be x . then , 3 ( 2 x + 9 ) = 57 2 x = 10 = > x = 5 answer : a"
divide(subtract(57, multiply(const_3, 9)), multiply(const_3, const_2))