if you're meaning a value between 11 and 20, write
11<x>20 and put a line under the < and > which indicates that x could also equal 11 or 20. x doesnt only have to be a value between 11 and 20, but it can equal the numbers too.
i dont think that makes a lot of sense but if you were to say the answer out loud, the answer would be "x (which is any value) is more than or equal to 11 and less than or equal to 20"
