1. The problem is to understand the difference between an algebraic expression and an algebraic equation, and solve the equation given. 2. An algebraic expression is a combination of numbers and variables without an equal sign, for example, $4 + n$. 3. An algebraic equation is a mathematical sentence that includes an equal sign, for example, $4 + n = 7$. 4. To solve the equation $4 + n = 7$, we want to find the value of $n$ that makes the equation true. 5. Subtract 4 from both sides of the equation: $$4 + n - 4 = 7 - 4$$ which simplifies to $$n = 3$$ 6. So, the value of $n$ that satisfies the equation is $3$. 7. This means the sum of 4 and 3 is 7, confirming the equation is true. Final answer: $n = 3$