1: \(\Leftrightarrow x^2-6x+9< x^2-5x+4\)
=>-x<-5
hay x>5
2: \(\Leftrightarrow x^2-9< =x^2+4x+4+3\)
=>4x+7>=-9
=>4x>=-16
hay x>=-4
3: \(\Leftrightarrow20x-25>21-3x\)
=>23x>46
hay x>2
Đúng 0
Bình luận (1)