Because of the properties of division, we know that a positive number divided by a positive number will be a positive number
\(\frac{1}{1} = 1\)
Likewise, a negative number divided by a negative number will be a positive number
\(\frac{-1}{-1} = 1\)
But a positive number divided by a negative number, or vice versa will be a negative number.
\(\frac{-1}{1} = \frac{1}{-1} = -1\)