Prealgebra (7th Edition)

$-2y^4-12y^3+8y$
$-2y(y^3+6y^2-4)\rightarrow$ use the distributive property =$(-2y)(y^3)+(-2y)(6y^2)-(-2y)(4)\rightarrow$ use the product property of exponents =$-2y^4-12y^3+8y$