the salary of a worker is first increased by 10 % and afterwards reduced by 10 % . what is the net change in the worker ' s salary ?
"let x be the original salary . the final salary is 0.9 ( 1.1 x ) = 0.99 x the answer is b ."
subtract(const_100, subtract(add(10, const_100), divide(multiply(add(10, const_100), 10), const_100)))