a number whose fifth part increased by 5 is equal to its fourth part diminished by 5 , is
"x / 5 + 5 = x / 4 - 5 = > x / 5 - x / 4 = 10 x / 20 = 10 = > x = 200 answer : c ."
divide(add(5, 5), subtract(divide(const_1, 5), divide(const_1, add(const_1, 5))))