Been stuck on this question for quite awhile. A detailed explanation will be much appreicated. Will give a like and thank you in advance.

(a) Implement a function in Python to create a dictionary: {a:10, 'b': 20,c:30, 'd': 40} and display each key-value pairs of it. (5 marks) (b) Implement a function dict_check_add(dictionary, key, value) in Python to check whether a key of the given key-value pair already exists in the dictionary. If it is not, add the key-value pair to the dictionary