Chapter 4 - Polynomials - 4.4 Addition and Subtraction of Polynomials - 4.4 Exercise Set - Page 260: 43

$8a^3+8a^2+a-4$

Removing the grouping symbols, then the given expression, $ (4a^2+a-7)-(3-8a^3-4a^2) $, is equivalent to \begin{array}{l} 4a^2+a-7+3+8a^3+4a^2 .\end{array} By combining like terms, then \begin{array}{l} 8a^3+(4a^2+4a^2)+a+(-7+3) \\\\= 8a^3+8a^2+a-4 .\end{array}