x(x2+6x+9) - 3x= x3+6x2+12x+8+1
\(\Leftrightarrow\)x3+6x2+9x-3x=x3+6x2+12x+9
\(\Leftrightarrow\)6x=12x+9
\(\Leftrightarrow\)6x=-9
\(\Leftrightarrow\)x=-3/2
Vậy phương trình có 1 nghiệm duy nhất x=-3/2
x(x + 3)^2 - 3x = (x + 2)^3 + 1
<=> x(x^2 + 6x + 9) = x^3 + 6x^2 + 12x + 8 + 1
<=> x^3 + 6x^2 + 9x = x^3 + 6x^2 + 12x + 9
<=> 3x + 9 = 0
<=> 3x = -9
<=> x = -3
\(x\left(x+3\right)^2-3x=\left(x+2\right)^3+1\)
\(\Leftrightarrow x\left(x^2+6x+9\right)=x^3+6x^2+12x+8+1\)
\(\Leftrightarrow x^3+6x^2+9x=x^3+6x^2+12x+9\)
\(\Leftrightarrow3x+9=0\)
\(\Leftrightarrow3x=-9\)
\(\Leftrightarrow x=-3\)