I have made this expression from nfa (NFA to regular expression) : (a+ab+aab)(a+aa) but at book answers it is written like this : (a+aab)(aa)
I am thinking that the my answer is same as book but they have converted it into it just like quadratic equation as we do. SO any one who can help me or book answer is wrong or mine is wrong BUT IF BOTH ARE SAME THEN TELL ME HOW TO CONVERT INTO BOOK FORM?