1. **State the problem:** Simplify the expression $9(-7t + 4t - 10) - 9t$. 2. **Apply the distributive property:** Multiply 9 by each term inside the parentheses. $$9(-7t) + 9(4t) + 9(-10) - 9t$$ 3. **Calculate each multiplication:** $$-63t + 36t - 90 - 9t$$ 4. **Combine like terms:** Combine all terms with $t$. $$(-63t + 36t - 9t) - 90$$ 5. **Simplify the coefficients:** $$(-63 + 36 - 9)t - 90$$ $$(-63 + 27)t - 90$$ $$-36t - 90$$ 6. **Final simplified expression:** $$\boxed{-36t - 90}$$