Question

what is the answer to this math problem 1/12-5/x

Answer 1

There would first have to be a question or at least an instruction.

Answer 2

I note that this is only an expression, not an equation, so you cannot "solve" this problem for a specific x value, or even for the function named x.
All you could do would be to COMBINE the two fractions into one, using the LCD.
Again, it's important that you include the instructions with your posts.