Question 448121
D U E = {x | x is a whole number or x is a perfect square < 10}


D U F = {x | x is a whole number or x is an even number between 10 & 20}



You can think of the union operation as an "or" operation.



Another example: Let A = {1,2} and B = {3,4}



So A U B = {1,2,3,4}. So it's like saying A U B = set A or set B