## Thinking Mathematically (6th Edition)

$A=\{x | x \text { is an odd natural number and } x<9\}$ according to the above statement set $A=\{1,3,5,7\}$ $U=\{x | x \in \mathbf{N} \text { and } x<9\}$ according to the above statement set $B=\{1,2,3,4,5,6,7,8\}$ The set $A \cup U$ is a set of all elements in $A\$and all element in $B$ that are not in $A$ $\therefore$ $A \cup U=\{1,2,3,4,5,6,7,8\}$
$A=\{x | x \text { is an odd natural number and } x<9\}$ according to the above statement set $A=\{1,3,5,7\}$ $U=\{x | x \in \mathbf{N} \text { and } x<9\}$ according to the above statement set $B=\{1,2,3,4,5,6,7,8\}$ The set $A \cup U$ is a set of all elements in $A\$and all element in $B$ that are not in $A$ $\therefore$ $A \cup U=\{1,2,3,4,5,6,7,8\}$