Respuesta :

(r^2- r^4)- (6r^4+ 2r^2)
= r^2 -r^4- 6r^4- 2r^2
= (r^2- 2r^2)+ (-r^4-6r^4)
= -r^2 -7r^4
= -r^2* (1+ 7r^2).

The final answer is -r^2* (1+ 7r^2).

Hope this helps~