Why net income/loss and most items always calculated as a positive value when calculating DuPont Analysis?

Hi,

Please, I hope that I am posting in the right forum.

I was reading the DuPont Analysis article

Please, my question is, does there is a reason for always adding a + sign before calculating the profit/loss and other items?

What if there is a net loss instead of a net profit?

Can I calculate DuPont if there is a net loss?

Thanks