Stupid question maybe, but how can you hide output of a for loop? The usual : does not work here... Thanks for your help.

Imagine you have to solve the following problem. xi*(a-(x1+x2+...+xi+...+xn)-b) However, we can not see ex ante that all the x's are the same. So, I would like to differentiate to xi and equal the derivative to zero. So, I should have xi in function of the other x's. I hope anyone can see what I mean and I beg you to answer me because this is very important for me. Thanks a lot. Greets Jan