1. **State the problem:** Simplify the expression $$(4x^3 + 3x - 1) - (-7x^3 + 2x^2 + 3x - 1 + 7x^3 - 2x^2 + 10)$$ 2. **Rewrite the expression inside the parentheses:** $$-7x^3 + 2x^2 + 3x - 1 + 7x^3 - 2x^2 + 10$$ 3. **Combine like terms inside the parentheses:** $$(-7x^3 + 7x^3) + (2x^2 - 2x^2) + 3x + (-1) + 10 = 0 + 0 + 3x + 9 = 3x + 9$$ 4. **Substitute back into the original expression:** $$(4x^3 + 3x - 1) - (3x + 9)$$ 5. **Distribute the minus sign:** $$4x^3 + 3x - 1 - 3x - 9$$ 6. **Combine like terms:** $$4x^3 + (3x - 3x) + (-1 - 9) = 4x^3 + 0 - 10 = 4x^3 - 10$$ **Final answer:** $$4x^3 - 10$$