Chapter 1 - Some Basic Concepts of Arithmetic and Algebra - 1.4 - Integers: Multiplication and Division - Problem Set 1.4 - Page 26: 45

69

Because multiplication is before addition in order of operations, we first multiply and then we add. We see that we are multiplying a negative number by a negative number in this problem. Recall, when we multiply two negative numbers, the negatives will cancel out, so the answer will always be positive. Thus, we obtain: $(-3)(-8)+(-9)(-5)=24+45=69$