1. **State the problem:** Simplify the expression $-3m^2 + 3m^2 - m + 2m$. 2. **Identify like terms:** Like terms are terms that have the same variable raised to the same power. Here, $-3m^2$ and $3m^2$ are like terms (both $m^2$ terms), and $-m$ and $2m$ are like terms (both $m$ terms). 3. **Combine like terms:** - For the $m^2$ terms: $-3m^2 + 3m^2 = 0$ - For the $m$ terms: $-m + 2m = ( -1 + 2 )m = 1m = m$ 4. **Write the simplified expression:** After combining, the expression simplifies to $m$. 5. **Conclusion:** The simplified form of the expression $-3m^2 + 3m^2 - m + 2m$ is $m$.