1. **Problem:** Simplify the algebraic expression $m + m + r + 7 - 3$. 2. **Formula and rules:** Combine like terms by adding or subtracting coefficients of the same variable and simplify constants. 3. **Step-by-step solution:** - Combine the $m$ terms: $m + m = 2m$ - Combine the constants: $7 - 3 = 4$ - The expression becomes: $$2m + r + 4$$ 4. **Explanation:** You add coefficients of the same variable and simplify constants separately. Here, $m$ terms add up to $2m$, $r$ stays as is, and constants $7$ and $-3$ combine to $4$. **Final answer:** $$2m + r + 4$$