2(x2+x+1)2-7(x-1)2=13(x3-1)
<=> 2(x2+x+1)2-7(x-1)2-13(x3-1)=0
<=>2(x2+x+1)2-14(x3-1)+(x3-1)-7(x-1)2=0
<=> 2(x2+x+1)(x2+x+1-7x+7)+(x-1)(x2+x+1-7x+7)=0
<=> (2x2+2x+2)(x2-6x+8)+(x-1)(x2-6x+8)=0
<=> (x2-6x+8)(2x2+3x+1)=0
<=> (x2-4x-2x+8)(2x2+2x+x+1)=0
<=> [x(x-4)-2(x-4)][2x(x+1)+(x+1)]=0
<=> (x-4)(x-2)(x+1)(2x+1)=0
Đến đây dễ rồi nhé bạn