Chapter 5 - Exponents and Polynomials - 5.1 - Addition and Subtraction of Polynomials - Problem Set 5.1 - Page 195: 26

$-5n^2+2n-13$

We write an expression to express this addition problem: $(-5n^2+7n-9)+(-5n-4)$ We use the commutative, associative, and distributive properties to group like terms: $(-5)n^2+(7+(-5))n+(-9+(-4))$ We combine the like terms within each set of parentheses: $-5n^2+2n+(-13)=-5n^2+2n-13$