Đáp án:
Giải thích các bước giải:
$a,(2x-3)^3=8x^3-36x^2+54x-27$
$b,x^3+8=(x+2)(x^2-2x+4)$
$c,8x^3-1=(2x-1)(4x^2+2x+1)$
$d,(3x+2)^2=27x^3+54x^2+36x+8$
Bài 2:
$a,(3x-1)^2-(3x+2)(3x-2)=2014$
$⇔(9x^2-6x+1)-(9x^2-4)=2014$
$⇔9x^2-6x+1-9x^2+4=2014$
$⇔-6x=2009$
$⇔x=-\dfrac{2009}{6}$
$b,(x+3)(x^2-3x+9)-x(x-2)(x+2)=15$
$⇔x^3+27-x(x^2-4)=15$
$⇔x^3-x^3+4x=-12$
$⇔x=-3$
$c,4x^2-12x+9=(5-x)^2$
$⇔(2x-3)^2-(5-x)^2=0$
$⇔(2x-3-5+x)(2x-3+5-x)=0$
$⇔(3x-8)(x+2)=0$
$⇔\left[ \begin{array}{1}3x=8\\x=-2\end{array} \right.$
$⇔\left[ \begin{array}{1}x=\dfrac{8}{3}\\x=-2\end{array} \right.$