1. **State the problem:** Solve the equation $2a + b = 10$ for one variable in terms of the other. 2. **Choose a variable to solve for:** Let's solve for $b$. 3. **Isolate $b$:** $$2a + b = 10$$ Subtract $2a$ from both sides: $$b = 10 - 2a$$ 4. **Explanation:** We moved $2a$ to the right side by subtracting it from both sides, isolating $b$. 5. **Result:** The solution for $b$ in terms of $a$ is: $$b = 10 - 2a$$ You can also solve for $a$ if needed: 6. **Solve for $a$:** $$2a + b = 10$$ Subtract $b$ from both sides: $$2a = 10 - b$$ Divide both sides by 2: $$a = \frac{10 - b}{2}$$ 7. **Intermediate step showing cancellation:** $$a = \frac{\cancel{10 - b}}{\cancel{2}}$$ (Here, no factors cancel, so this is just to show division by 2.) 8. **Result:** $$a = \frac{10 - b}{2}$$