Chapter R - Review of Basic Concepts - R.3 Polynomials - R.3 Exercises - Page 33: 54

$$-6x^{3}-3x^{2}-4x+4$$

Initial equation: $$-(8x^{3}+x-3)+(2x^{3}+x^{2})-(4x^{2}+3x-1)$$ Distribute the signs located in front of the parenthesis: $$-8x^{3}-x+3+2x^{3}+x^{2}-4x^{2}-3x+1)$$ Then combine like terms to arrive at the final answer: $$-6x^{3}-3x^{2}-4x+4$$