Find a ∩ b if a = {4, 7, 10, 13, 17} and b = {3, 5, 7, 9}.

{7}.

Explanation: The union of two sets is a new sets that contains all the elements that are at least in one of the sets (without repeating elements) for example {1, 2, 3}∪{2, 3, 4}={1, 2, 3, 4}. The intersection of two sets is a new set that contains the elements that are in both sets, for example: {1, 2, 3}∩{2, 3, 4}={2, 3}. In the given exercise we have an intersection of two sets, so the answer is the common elements in both sets, in this case the only common element is number 7 so:

{4, 7, 10, 13, 17} ∩ {2, 5, 7, 9} = {7}

The merge of two sets is a new set that has all the elements that are at least in one of the sets w/out repeating elements. The intersection of two sets is a new set that has the elements in both of the sets because {1, 2, 3}∩{2, 3, 4}={2, 3}. In this case the only common element is number 7 so: {4, 7, 10, 13, 17} ∩ {2, 5, 7, 9} = {7}.

old english did not sound like modern english, which differs widely in phonology and especially in grammar, so taht old english is unintelligible to modern speakers.

the average english was strongly influenced by the anglo-norman as later by the anglo-french. the pronunciation was affected by the norman with the sounds   "/ θ / and / ð / " transcribed as th.

modern english was standarized from the london dialect and extended by the government and administartion as well as by the effects of printing, began to acquire more words from other languages as well to imporve in a more fluent pronunciation.