Whats the answer to 1/5x=121 x=?

You have an algebraic expression in which you are solving for x.  When you are solving for a variable, you need to isolate it all alone.  Since you are multiplying by 1/5, you will have to undo it by multiplying by its reciprocal.  In this case you are multiplying both sides by 5/1.

5/1 *1/5x = 121*5/1
x = 605

To check your answer, plug this value in for x and multiply it by 1/5.  You should arrive at 121!  Good luck!