what is e[x]x=x$ what is the proof that x is a variable how to prove for x=x what is the proof of $[x] is x$ proof that x and x equal x why is $x=x$ how to prove that x is x? which variable is $x$ how do i test the assumption of $$X$ if $$E[x|x]=x$, then what variable is $X$? how do you prove that X = X proof that e[x]=x proof for the statement $$E[x] = x proof for xx = x what is the proof of x = x what is the proof for the variable x? what is the probability of x = x in ec why does $x$ represent x$ what is the proof for x = xx what is $$E[x]=x$