Respuesta :

(-4 x^3 y^3 ) ( -9 x^3 y^3 )
Multiplying two negative signs gives positive
(-) . (-) = (+)
4 x^3 y^3 . 9 x^3 y^3
4.9.x^3.x^3.y^3.y^3
36 x^6 y^6
This is a answer