Chapter 4 - Polynomials - 4.4 Addition and Subtraction of Polynomials - 4.4 Exercise Set - Page 260: 36

$6a^3-0.2a^2+7$

Since the expression in parenthesis is preceded by a negative sign, then all terms inside the parenthesis will alter its sign when the parenthesis is removed. Hence, the given expression, $ -(-6a^3+0.2a^2-7) $, is equivalent to \begin{array}{l} 6a^3-0.2a^2+7 .\end{array}