Question 824140
"U" indicates a union of sets.
"set1 U set2" is a reference to a third set which is composed of all the elements of set1 and set2 which are elements of either set1 or set2 or are elements of both set1 and set2.<br>
X U Y = {-5, 15, 22, 33, 44, 89, 99, 150, 160, 165, 1025}
is a false statement because it is missing 88 which is an element of set Y.<br>
&#8745; indicates an intersection of sets
"set1 &#8745; set2" is a reference to a third set which contains only those elements which are members of <u>both</u> set1 and set2.
X &#8745; Y = {15, 33, 1025}
is a true statement because 15, 33 and 1025 are the only elements of X and Y which are elements of both X and Y.<br>
"Ø" is a symbol used to indicate an empty set.
"&#8834;" is a symbol which says "is a subset of"
Ø &#8834; (X U Y)
is a true statement because the empty set is considered a subset of <u></u> sets.