What is the surface area of a rectangular prism that measures 10 in x 6 in x 4 in?

Solve for x i'll try to attach the files bc it's not letting me for some reason

The volume of gas a balloon can hold varies directly as the cube of its radius. imagine a balloon with a radius of 3 inches can hold 81 cubic inches of gas. how many cubic inches of gas must be released to reduce the radius down to 2 inches?

Prove that (x-2)is factor of p (x)=2x³-3x²-17x+30