Answer
The sum of two negative decimals can never be positive because when you add two negative decimals together the result is another negative decimal.
Work Step by Step
As an example, let's add $-4.50$ and $-5.73$.
$$-4.50 + (-5.73) = -$10.23$$
The process of adding two negative numbers can be thought of as simply adding two numbers and then adding the negative sign in front of it.
If you have two variables, $-a$ and $-b$, and you are adding them together.
$$-a + (-b)$$
You can factor out $-1$ from the two variables.
$$-1(a + b)$$
This is simply a reaffirmation of why adding negative numbers will always result in a sum of another negative number.
