M8D1. c.Use set notation to denote elements of a set

• Give a solution using the roster method:A = { 1, 2, 3, 4, 5, 6, 7 }, B is a subset of A, the elements of B are even. The numbers in A that are even are 2, 4, and 6, so B = {2, 4, 6}.

• What is the intersection of A = { x is odd } and B = { x is between –4 and 6 }, where the elements of the two sets are integers? Since "intersection" means "only things that are in both sets", the intersection will be all the numbers which are both odd and between –4 and 6.
  
  {–3, –1, 1, 3, 5}

• What is the union of A = { x is a natural number between 4 and 8 inclusive }and B = { x is a single-digit negative integer }? Since "union" means "anything that is in either set", the union will be everything from A plus everything in B. Since A = { 4, 5, 6, 7, 8 } and B = { –9, –8, –7, –6, –5, –4, –3, –2, –1 }, then their union is:
  
  { –9, –8, –7, –6, –5, –4, –3, –2, –1, 4, 5, 6, 7, 8 }