1. **State the problem:** Simplify the expression by combining like terms: $$-9m + 5.5n - 3n - 4.7m^2 + 6m - 8.1n$$ 2. **Identify like terms:** Like terms have the same variable and exponent. - Terms with $m$: $-9m$ and $6m$ - Terms with $n$: $5.5n$, $-3n$, and $-8.1n$ - Term with $m^2$: $-4.7m^2$ 3. **Combine like terms:** - Combine $m$ terms: $$-9m + 6m = \cancel{-9m} + \cancel{6m} = -3m$$ - Combine $n$ terms: $$5.5n - 3n - 8.1n = \cancel{5.5n} - \cancel{3n} - 8.1n = (5.5 - 3 - 8.1)n = -5.6n$$ - The $m^2$ term remains as is: $-4.7m^2$ 4. **Write the simplified expression:** $$-3m - 5.6n - 4.7m^2$$ 5. **Check Aisha's work:** - Aisha's answer was $-3m + 2.5n - 4.7m^2$ - She combined $m$ terms correctly. - She combined $n$ terms incorrectly; she got $2.5n$ instead of $-5.6n$. - She did not forget the $-8.1n$ term; she combined it incorrectly. **Conclusion:** Aisha made a mistake combining the $n$ terms. **Final answer:** $$\boxed{-3m - 5.6n - 4.7m^2}$$