simplify each expression
(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~
