robert ' s salary was decreased by 30 % and subsequently increased by 30 % . how much percentage does he lose ?
"let original salary be $ 100 salary after decreasing 30 % = 100 - 100 x 30 / 100 = $ 70 salary after increasing 30 % on $ 70 = 70 + 70 x 30 / 100 = $ 91 percentage of loss = 100 - 91 = 9 % answer : b"
multiply(divide(subtract(multiply(const_100, const_100), multiply(subtract(const_100, 30), add(const_100, 30))), multiply(const_100, const_100)), const_100)