Solve (-15)+(-5): Adding Negative Numbers on a Number Line

Let's first locate the number negative 15 on the number line.

Now let's deal with the operation in the exercise, given that the operation is $+(-5)$

Since negative 5 is less than 0, we will move five steps to the left from negative 15, where each step represents one whole number as follows:

We can see that the number we reached is negative 20.