\(< =>\left(\left(x+2\right)^3-\left(x-2\right)^3\right)-16-108=0\)
\(< =>\left(x+2-x+2\right)\left(\left(x+2\right)^2+\left(x+2\right)\left(x-2\right)+\left(x-2\right)^2\right)-16-108=0\)
\(< =>4\left(x^2+4x+4+x^2-4+x^2-4x+4\right)-16-108=0\)
\(< =>4\left(3x^2+4\right)-16-108=0\)
\(< =>12x^2+16-16-108=0\)
\(< =>12x^2-108=0\)
\(< =>12\left(x^2-9\right)=0\)
\(< =>x^2-9=0\)
\(
< =>\left(x-3\right)\left(x+3\right)=0\)
\(< =>\orbr{\begin{cases}x-3=0\\x+3=0\end{cases}< =>\orbr{\begin{cases}x=3\\x=-3\end{cases}}}\)
(x+2)3-(x-2)3-16=108
x3+3x2.2+3.x.22+23-x3+3x2.2-3.x.22+23=124
(x3-x3)+(6x2+6x2)+(12x-12x)+(8+8)=124
12x2+16=124
12x2=108
x2=9
x=-3 hoặc x=3
x3 +6x2 + 12x + 8 - x3 +6x2 - 12x +8 -16 = 108
12x2 = 108
x2 = 9
x = +- 3
