(2x 3﹣3x 2y﹣2xy 2)﹣(x 3﹣2xy 2+y 3)+(﹣x 3+3x 2y﹣y 3)
=2x 3﹣3x 2y﹣2xy 2﹣x 3+2xy 2﹣y 3﹣x 3+3x 2y﹣y 3
=(2﹣1﹣1)x 3+(﹣3+3)x 2y+(﹣2+2)xy 2+(﹣1﹣1)y 3
=﹣2y 3,
故代数式的值与x的取值无关.
(2x 3﹣3x 2y﹣2xy 2)﹣(x 3﹣2xy 2+y 3)+(﹣x 3+3x 2y﹣y 3)
=2x 3﹣3x 2y﹣2xy 2﹣x 3+2xy 2﹣y 3﹣x 3+3x 2y﹣y 3
=(2﹣1﹣1)x 3+(﹣3+3)x 2y+(﹣2+2)xy 2+(﹣1﹣1)y 3
=﹣2y 3,
故代数式的值与x的取值无关.