Chapter SR1, Problem 18P

Solution

To perform the indicated operation in the expression $-23+\left(-5\right)$ .

  $-28$

Given:

The expression, $-23+\left(-5\right)$ .

Concept Used:

Rules of Addition/ Subtraction:

• Two numbers with similar sign always get added and the resulting number will carry the similar sign.
• Two numbers with opposite signs always get subtracted and the resulting number will carry the sign of larger number.

Rules of Multiplication/ Division:

• The product/quotient of two similar sign numbers is always positive.
• The product/quotient of two numbers with opposite signs is always negative.

Calculation:

In order to simplify the given expression $-23+\left(-5\right)$ , note that the sign of both numbers is same, so add the numbers and keep the similar sign with the resulting number as shown below

  $\begin{array}{c}-23+\left(-5\right)=-\left(23+5\right)\\ =-\left(28\right)\\ =-28\end{array}$

Thus, the simplified expression is $-28$ .