This test is wrong:
Right result: ["7xxx+14xx+88x+302","1401x+2718"]
Fail: checkio(["7xxxxx-3xxx+5x","xx-3x-9"])
I am quite sure because I added my own validation using 'eval'. You can verify with x=1
Created at: 2013/06/05 05:44; Updated at: 2013/09/30 13:47