1. **State the problem:** A textbook store sold a total of 480 history and physics textbooks in a week. The number of history textbooks sold was two times the number of physics textbooks sold. We need to find how many textbooks of each type were sold. 2. **Define variables:** Let $p$ be the number of physics textbooks sold. Let $h$ be the number of history textbooks sold. 3. **Write the equations based on the problem:** - Total textbooks sold: $$h + p = 480$$ - History textbooks relation: $$h = 2p$$ 4. **Substitute the second equation into the first:** $$2p + p = 480$$ 5. **Simplify and solve for $p$:** $$3p = 480$$ $$p = \frac{480}{3} = 160$$ 6. **Find $h$ using $h = 2p$:** $$h = 2 \times 160 = 320$$ 7. **Answer:** - Number of history textbooks sold: 320 - Number of physics textbooks sold: 160 This means the store sold 320 history textbooks and 160 physics textbooks that week.