Answer
$\overline{A} \cup \overline{B}=\left\{0, 1, 2, 3, 5, 6, 7, 8, 9\right\}$
Work Step by Step
RECALL:
(1) $\overline{B}$ is the complement of set $B$, which is the set that contains the elements of the universal set that are not elements of $B$.
(2) $\cup$ represents the union of two sets, which is the set that contains the combined elements of the two given sets.
Use (1) above to obtain:
$\overline{A}=\left\{0, 2, 6, 7, 8\right\}$
$\overline{B} = \left\{0, 1, 3, 5, 9\right\}$
Use rule (2) above to obtain:
$\overline{A} \cup \overline{B}=\left\{0, 1, 2, 3, 5, 6, 7, 8, 9\right\}$
