a man is 30 years older than his son . in three years , his age will be twice the age of his son . the present age of his son is :
"let the son ' s present age be x years . then , man ' s present age = ( x + 30 ) years . ( x + 30 ) + 3 = 2 ( x + 3 ) x + 33 = 2 x + 6 x = 27 . answer : c"
divide(subtract(30, subtract(multiply(const_2, const_2), const_2)), subtract(const_2, const_1))