Chapter 4 - Polynomials - 4.4 Addition and Subtraction of Polynomials - 4.4 Exercise Set - Page 260: 45

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Removing the grouping symbols, then the given expression, $ (7x^3-2x^2+6)-(6-2x^2+7x^3) $, is equivalent to \begin{array}{l} 7x^3-2x^2+6-6+2x^2-7x^3 .\end{array} By combining like terms, then \begin{array}{l} (7x^3-7x^3)+(-2x^2+2x^2)+(6-6) \\\\= 0x^3+0x^2+0 \\\\= 0 .\end{array}