The negative in front of the second bracket means that it's times by -1 so each of their signs switches: 3m^2+2n-m^2-2n Add like terms 2m^2 the 2n cancels out
The answer would be 1017.88 in³. Use the volume for cones ( 1/3 times pi times radius times height) so 1/3*3.14*9*12 in which would be 1017.88 in³ hope it helps!
