Smoo
Fear the Beaver
If -5 cannot be -5 and has to be (-1)(5) then all you've done is create an infinite regression which makes solving the expression impossible. Because then -1 cannot be -1, it has to be (-1)(1). But then the -1 in that expression cannot be -1, it also has to be (-1)(1). And so on. It is clear at some point that you have to accept that a number can be inherently negative. And once you've made that assumption, there's no need for the initial factoring, the -5 can be inherently negative.