Solve -30-(-10): Working with Double Negatives in Subtraction

Let's remember the following rule:

$-(-x)=+$

Now let's write the exercise in the appropriate form:

$-30+(10)=$

We'll locate the number negative 30 on the number line.

We'll move 10 steps to the right (since 10 is greater than zero):

We can see that we've arrived at the number negative 20.