1、X4-2X3+3X2-2X+1＞0
X3(X-2)+X(X-2)+2X2+1＞0
X(X-2)(X2+1)+X2+1+X2＞0
(X2-2X+1)(X2+1)+X2＞0
(X-1)2(X2+1)+X2＞0
X=0时,X-1≠0,X-1=0时,X≠0,
所以X取任意数(X-1)2(X2+1)+X2＞0都成立
2、x3-X2＜0
x2(x-1)＜0
x-1＜0,x≠0
x＜1,x≠0
所以x＜1,x≠0,x3-X2＜0成立
3、X3-9X2-8X+72＜0
X2(X-9)-8(X-9)＜0
(X2-8)(X-9)＜0
(X+8)(X-8)(X-9)＜0
X+8＜0,X-9>0或者X+8>0,X-80或者X+8>0,X-8>0,X-9-8,X9不成立
X>-8,X>8,X