Chapter 4, Problem 17QC

To determine

To find: Sum of the given expression

Answer to Problem 17QC

  $-21$

Explanation of Solution

Given information:

  $-13+\left(-8\right)$

Calculation:

We know product of numbers with same sign is always positive and product of numbers with opposite sign is always negative.

Sum of the given expression can be calculated as shown:

  $\begin{array}{l}-13+\left(-8\right)=-13-8\mathrm{...}\left[(-)·(+)=(-)\right]\\ \Rightarrow -13+\left(-8\right)=-21\end{array}$