Given the problem:
What expression is equivalent to -5-(-4)
Whenever you see a number subtracting a negative number, simply draw two vertical lines down the minus signs. They become positives. All you have to do is add the numbers.
Or you can see why that happens. You have -5-(-4). Look at it. To solve this, you will distribute first. Negative times a negative makes a positive. So you get -5+4. Solve that and you get -1.
So the expression is -5+4, which equals -1.
Hope this helped!