-1 x -1

means

-1 is added to itself -1 times

(just as 2x2 means 2 is added to itself 2 times)

means -1 is subtracted from itself 1 time

in other words

i can say it like dat

1 is subracted from itself -1 time]

or

1 is added to itself 1 time

this is equal to 1

this is applicable for ne two -ve quantities ....just as u asked

....this is all ORIGINAL