3) 4xm−nm-nm−n - m + n4xm−nm-nm−n - m−nm-nm−n m−nm-nm−n4x−14x-14x−1
4) xa−ba-ba−b + a - bxa−ba-ba−b + 1a−ba-ba−b a−ba-ba−bx+1x+1x+1
3) 4xm−nm-nm−n - m + n
4xm−nm-nm−n - m−nm-nm−n m−nm-nm−n4x−14x-14x−1
4) xa−ba-ba−b + a - b
xa−ba-ba−b + 1a−ba-ba−b a−ba-ba−bx+1x+1x+1