When multipling signed numbers how do you know wether the number is positive or neagitive

If an odd number of minus signs are involved in a product or quotient, the sign of the result is negative. Otherwise, it is positive.

Examples:

(-1) (-1) = 1

(-1) (-1) (-1) = - 1

(-1) / (-1) = 1

(-1) (-1) / (-1) = - 1

The product of two positive numbers is positive: (+) (+) = (+).

The product of one positive number and one neg number is neg: (+) (-) = (-).

The product of two negative numbers is positive: (-) (-) = (+)