Question

if A={1, 2,3,4} and B={3,4,5,6,7} find 1)AUB 2) ANB 3) A-B 4) B-A. ​

Answer 1

Step-by-step explanation:

A)AUB={1,2,3,45,6,7}

B)ANB={3,4}

C)A-B={1,2}

D)B-A={3,4}

Answer 2

Answer:

$A\cup B=\{1, 2,3,4,5,6,7\}$, $A\cap B=\{3,4\}$, $A-B=\{1,2\}$, $B-A=\{5,6,7\}$

Step-by-step explanation:

Given $A=\{1, 2,3,4\}$ and $B=\{3,4,5,6,7\}$

    1)  When two sets A and B are given, the union is the set of all the elements which are in either A or in B.

                      $A\cup B=\{1, 2,3,4\} \cup\{3,4,5,6,7\}$

                                 $=\{1, 2,3,4,5,6,7\}$

    2) When two sets A and B are given, the intersection is the set of all elements which are common in A and B.

                      $A\cap B=\{1, 2,3,4\} \cap\{3,4,5,6,7\}$

                                 $=\{3,4\}$

    3) When two sets A and B are given, the difference between the sets  consists of the elements of A that are not in B.

                       $A - B=\{1, 2,3,4\} -\{3,4,5,6,7\}$

                                  $=\{1,2\}$

   4) The difference between the sets consists of the elements of B that are not in A.

                        $B- A=\{3,4,5,6,7\}-\{1, 2,3,4\}$

                                   $=\{5,6,7\}$