1. **State the problem:** Solve the equation involving the numbers 6 and 2.5. Since the user did not specify the exact problem, let's consider a common algebraic problem: find the sum of 6 and 2.5. 2. **Formula used:** To find the sum of two numbers $a$ and $b$, use the formula: $$a + b$$ 3. **Apply the formula:** $$6 + 2.5$$ 4. **Calculate the sum:** $$6 + 2.5 = 8.5$$ 5. **Conclusion:** The sum of 6 and 2.5 is 8.5.