A.x2-x+1>0 | B.-2x2+x+1>0 | C.2x-x2>5 | D.x2+x>2 |
1 |
2 |
3 |
4 |
A.{x|-2≤x≤
| B.{x|-2≤x<
| ||||
C.{x|x>2或x≤-
| D.{x|x≤-2或x≥
|
A.(-∞,0) | B.(-∞,0)∪(
| C.(-∞,0] | D.(-∞,0]∪[
|
A.{x|-4≤x<-2或3<x≤7} | B.{x|x≤-2或x>3} |
C.{x|-4<x≤-2或3≤x<7} | D.{x|x<-2或x≥3} |
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