a: =>3x^2-2x-1>0
=>3x^2-3x+x-1>0
=>(x-1)(3x+1)>0
=>x>1 hoặc x<-1/3
b:=>36x^2-12x+1<=0
=>(6x-1)^2<=0
=>6x-1=0
=>x=1/6
c: =>x^2-6x+9>0
=>(x-3)^2>0
=>x<>3
d: =>(x-3)(x+3)<0
=>-3<x<3
e: =>(x-2căn 2)^2<0(loại)
f: =>x^2-6x-7<=0
=>(x-7)(x+1)<=0
=>-1<=x<=7
g: =>2x^2+8x+4-2x-7/2>=0
=>2x^2+6x+1/2>=0
=>4x^2+12x+1>=0
=>\(\left[{}\begin{matrix}x< =\dfrac{-3-2\sqrt{2}}{2}\\x>=\dfrac{-3+2\sqrt{2}}{2}\end{matrix}\right.\)
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