Cách 1:
x+12x+6+2x+3x2+3xx+12x+6+2x+3x2+3x
=x(x+1)2x(x+3)+2(2x+3)2x(x+3)=x(x+1)2x(x+3)+2(2x+3)2x(x+3)
=x2+x2x(x+3)+4x+62x(x+3)=x2+x2x(x+3)+4x+62x(x+3)
=x2+x+4x+62x(x+3)=x2+x+4x+62x(x+3)
=x2+5x+62x(x+3)=x2+5x+62x(x+3)
=x2+2x+3x+62x(x+3)=x2+2x+3x+62x(x+3)
=(x+2)(x+3)2x(x+3)=(x+2)(x+3)2x(x+3)
=x+22x=x+22x
Cách 2:
X+1 =2x +3 =x' +3x =2x + 62 =36