Question

can u solve this question if yes

Answer 1

648 and 8640 are not perfet cubes because their factors do mot make pairs of 3-3

Answer 2

do prime factorization of each option and group them in threes.....
648=2*2*2*3*3*3*3
when we group them we get two pairs of 2 and 3 but one extra 3....so it is not a perfect cube.
729=3*3*3*3*3*3
here we get two pairs of 3 hence it it is a perfect cube of 3*3=9
8640=2^6*3^3*5
here we get an extra 5 which is unpaired so it ain't a cube
8000=2^6*5^3
here we get two pairs of 2 and one pair of 5 so it is a cube of2*2*5=20.....
hence in this way we complete with the answer....




thanks Mark as brainliest