1. **Problem:** Given the equation $x + 2y = 13$ and the solution point $(5,y)$, find the value of $y$. 2. **Formula and rules:** Substitute $x=5$ into the equation and solve for $y$. 3. **Substitution:** $$5 + 2y = 13$$ 4. **Isolate $y$:** $$2y = 13 - 5$$ $$2y = 8$$ 5. **Divide both sides by 2:** $$y = \frac{8}{2}$$ 6. **Simplify:** $$y = 4$$ 7. **Answer:** The value of $y$ is 4, which corresponds to option [A].