Chapter 5 - Exponents and Polynomials - 5.1 - Addition and Subtraction of Polynomials - Problem Set 5.1 - Page 195: 20

$-3a+3$

We write an expression to express this addition problem: $3a^2+4a-7+(-3a^2-7a+10)$ We use the commutative and associative properties of addition to group like terms: $(3a^2+(-3a^2))+(4a+(-7a))+(-7+10)$ We combine the like terms: $0-3a+3=-3a+3$