a, (2x+1)2=4x2+2x
<=>4x2+4x+1=4x2+2x
<=>4x2-4x2=4x-2x=-1
<=>2x=-1
<=>x=-1/2
vay X=1/2
b, x+2/4+2x-3/3=x-12/6
MTC=12
<=> 3(x+2)/12+4(2x-3)/12=2(x-12)/12
=>3(x+2)+4(2x-3)=2(x-12)
<=>3x+6+8x-12=2x-24
<=>3x+8x-2x=-6+12-24
<=>9x=-18
<=>x=-2
d, 9X2=(3X+2)(x-3)=4
<=>9X2=3X2-9X+2X-6+4
<=>9X2-3X2=-9X+2X=6-4
<=>3X2-7X+2
<=>3X2-6X-X+2
<=>(3X2-6X)(X-2)
<=>3X(X-2)(X-2)
<=>(X-2).3X
<=>3X2-6X
