Question

In the following exercise, simplify each expressions.

(a) $27-\left(-18\right)$

(b)$27+18$

Short answer

Part (a) The simplified value is 45.

Part (b) The simplified value is 45.

Step-by-step solution

Part (a) Step 1. Concept Used. 

According to subtraction property, the subtraction of a number is equal to the addition of its opposite. This can be expressed as follows.

$a-b=a+\left(-b\right)$

Part (a) Step 2. Calculation.

Add the opposite of the opposite of 18 with 27.

$\begin{array}{rcl}27-\left(-18\right)& =& 27+18\\ & =& 45\end{array}$

Part (b) Step 1. Calculation. 

Add the numbers 27 and 18.

$27+18=45$

Part (b) Step 2. Conclusion. 

The simplified value of$27+18$is 45.