1. **Problem:** Find the next number in the sequence: -4, -1, 4, 11, 20, ... 2. **Step 1:** Identify the pattern by finding the differences between consecutive terms: $$-1 - (-4) = 3$$ $$4 - (-1) = 5$$ $$11 - 4 = 7$$ $$20 - 11 = 9$$ 3. **Step 2:** The differences are 3, 5, 7, 9 which increase by 2 each time. 4. **Step 3:** The next difference should be $9 + 2 = 11$. 5. **Step 4:** Add this to the last term: $$20 + 11 = 31$$ 6. **Answer:** The next number is **31**. --- **Final answer:** 31