A human has to have the concept of maths and what a mathematical problem is. The calculator knows nothing about the concept of maths or problems and it must be fed the problem in exactly the right format and only gives the output in a single format.
Math is simply a set of rules, with some taking precedence over others. The way you solve an equation, and the way the calculator solves an equation is exactly the same.If your calculator needs input in a special format, you need to get a better calculator.