1. **State the problem:** We have universal set $U = \{1, 2, 3, 4, 5, 6, 7, 8, 9, 10\}$, sets $A = \{3, 5, 7, 10\}$ and $B = \{2, 3, 5, 8, 10\}$. We want to find $(A \cap B)'$ using De Morgan's Law. 2. **Recall De Morgan's Law:** $$(A \cap B)' = A' \cup B'$$ where $A'$ and $B'$ are complements of $A$ and $B$ relative to $U$. 3. **Find complements:** - $A' = U \setminus A = \{1, 2, 4, 6, 8, 9\}$ - $B' = U \setminus B = \{1, 4, 6, 7, 9\}$ 4. **Find union of complements:** $A' \cup B' = \{1, 2, 4, 6, 7, 8, 9\}$ 5. **Final answer:** $$(A \cap B)' = A' \cup B' = \{1, 2, 4, 6, 7, 8, 9\}$$