a: =>4x^2+4x+1-2x-1-2=0
=>4x^2-2x-2=0
=>2x^2-x-1=0
=>2x^2-2x+x-1=0
=>(x-1)(2x+1)=0
=>x=1 hoặc x=-1/2
b: =>(x^2-3x+3)(x^2-3x+2)=0
=>(x-1)(x-2)=0
=>x=1 hoặc x=2
c: =>(x^2-x)^2-(x^2-x)-2=0
=>(x^2-x-2)(x^2-x+1)=0
=>(x-2)(x+1)=0
=>x=2 hoặc x=-1
d: =>(2x-5)^2-2(2x-5)-8=0
=>(2x-5-4)(2x-5+2)=0
=>(2x-9)(2x-3)=0
=>x=3/2 hoặc x=9/2