Respuesta :

The rule of product states that:

  • [tex] (+) \cdot (+) = (+) [/tex]
  • [tex] (+) \cdot (-) = (-) [/tex]
  • [tex] (-) \cdot (+) = (-) [/tex]
  • [tex] (-) \cdot (-) = (+) [/tex]

So, a product is positive if and only if both factors have the same sign, and is negative if only if the factors have opposite sign.