Question 1196396

Use the sets to find 
Let D​={4​,7​,9​}
E=​{4​,6​,7​,8​}
 F=​{3​,5​,6​,7​,9​}


first find (D ∪  E)  which  is defined as the set that consists of all elements belonging to either set D or set E (or both)

so,

(D ∪  E) ={4​,6​,7​,8,9​}


recall: The set A ∩ B—read “A intersection B” or “the intersection of A and B”—is defined as the set composed of all elements that belong to both A and B. 


in your case A=(D ∪  E)  and B= F

so, you have

(D ∪  E)  ∩ F={4​,6​,7​,8,9​} ∩ {3​,5​,6​,7​,9​}={6​,7​,9​}