Puzzle of the Week: Strange Addition

Each letter represents a number. Can you decode the Kyptogram?

Mathematics means abstraction. And that's why many mathematicians prefer to use letters instead of numbers.

In this puzzle of the week is also calculated with numbers. But in a different way than usual. In the so-called cryptogram above each of the three letters x, y and z stands for a digit greater than zero. For example, xx forms a two-digit number in which the digit x occurs twice.

You should find all the solutions of the cryptogram shown above. Is there a solution or several? Or maybe none?

REF: http://www.spiegel.de/wissenschaft/mensch/seltsame-addition-xx-yy-zz-xyz-raetsel-der-woche-a-1259058.html