Chapter 4 - Section 4.2 - Adding and Subtracting Polynomials - 4.2 Exercises - Page 286: 82

$-9m^3-6m^2+6m$

Removing the grouping symbols and then combining like terms, the given expression, $ [-(4m^2-8m+4m^3)-(3m^2+2m+5m^3)]+m^2 ,$ simplifies to \begin{array}{l}\require{cancel} [-4m^2+8m-4m^3-3m^2-2m-5m^3]+m^2 \\\\= -4m^2+8m-4m^3-3m^2-2m-5m^3+m^2 \\\\= (-4m^3-5m^3)+(-4m^2-3m^2+m^2)+(8m-2m) \\\\= -9m^3-6m^2+6m .\end{array}