Final answer:
To calculate the sum of -2 and -18, add the absolute values to get 20 and apply the negative sign, resulting in -20.
Step-by-step explanation:
The question involves adding two negative numbers together, which is a basic arithmetic operation in mathematics. According to the rules for addition, when you add two negative numbers, the sum also has a negative sign. For the numbers given in the question, which are -2 and -18, you simply add their absolute values together and then apply the negative sign to the result.
To find the sum of -2 and -18, we perform the following steps: