unfamiliar symbols!

<h1>x = -x+1</h1>

<h1>(#x) =</h1>

<p>the answer is apparently x..</p>

<p>anyone know the logic?</p>

<p>treat #x as a function. #(#x) is a composite function. substitute whatever is in the parenthesis. since #x = -x + 1 then #(#x) = -(-x + 1) + 1 = x - 1 + 1 = x</p>

<p>a composite function, of course! thank you! that was driving me crazy!</p>

<p>No problem. PM me if you have any questions.
btw I’m from Europe too :)</p>