Negative Property of Multiplication — Definition & Examples

Observe what happens when we multiply an even amount of $(-1)$'s together in the following examples: $$(-1)\cdot(-1)\cdot(-1)\cdot(-1)\cdot(-1)\cdot(-1)=1$$ $$(-1)\cdot(-1)\cdot(-1)\cdot(-1)\cdot(-1)\cdot(-1)\cdot(-1)\cdot(-1)=1$$