Chapter 8 - Polynomials and Factoring - 8-2 Multiplying and Factoring - Practice and Problem-Solving Exercises - Page 483: 14

$-56y^5+32y^4+8y^3$

We start with the given expression: $-8y^3(7y^2-4y-1)$ We apply the distributive property: $(-8y^3)(7y^2)+(-8y^3)(-4y)+(-8y^3)(-1)$ We multiply the coefficients and add the exponents: $-56y^5+32y^4+8y^3$