Can someone solve these problems and explain them? Problem#1: Find a regular expression corresponding to each of the following subsets of {a,b}*.

-The language of all strings that do not end with ab.

-The language of all strings not containing the substring aa.

Thank you in advance.

Problem\#2: Consider the following regular expression. 1. (b+ab)(a+ab) a. Generate the string bbbab and show how many times the first and second star will be evaluated. b. Generate the string abbbbbaaaab and show how many times the first and second star will be evaluated Give all steps. 2. Find a string of minimum length in {a,b} not in the following languages given in regular expressions. a. (a)(ba)(b) b. (b)(a+ba)(b)