Please explain your answers so that I can learn from it.

4. [35 points] Give regular expressions for each of the following languages. Use the syntax from this course, not any syntax you may have seen used in particular programming languages or text editors. 4a. [7 points] {w{a,b,c}:w consists of two or three b 's, followed by one or more c 's, followed by an optional a} 1 4b. [7 points] {w{a,b,c}:w2 and the first and last symbols of w are different } 4c. [7 points ]w{0,1}:w has no two consecutive 1s} 4d. [7 points] {w{0,1}:w has at least two 0 s and at most one 1} 4e. [7 points ]{w{0,1} : it is not true that w contains both 01 and 10 as substrings }