ii Find the union of the sets. 11, 3U12, 4) Choose the correct answer below. O A. {1, 3U12, 4t - 12, 4) O D. {1, 3)UK2, 4) (1, 2, 3, 4) Solution 1. {1,3}U{2,4} combining of all the distinct elements of the two sets is the union of the two sets. {AUB}={x|xA or xB} For ex : A={red,blue,green} and B ={yellow , green} Then {A}U{B} = { red ,blue ,green,yellow} Therefore, the answer of this question is (D) : {1,3}U{2,4}={1,2,3,4}. 2. {x|x^2=81} x^2=81; x=-9,+9. So, this resulting set represents the value of x and is equal to {-9,+9}..