$(x-4)(6-8x)=0$
$⇔$ \(\left[ \begin{array}{l}x-4=0\\6-8x=0\end{array} \right.\)
$⇔$ \(\left[ \begin{array}{l}x-4=0\\8x=6\end{array} \right.\)
$⇔$ \(\left[ \begin{array}{l}x=4\\x=\frac{3}{4}\end{array} \right.\)
$Vậy...$
$--$
$(x+7)^3 =-8$
$⇔(x+7)^3=(-2)^3$
$⇔x+7=-2$
$⇔x=-9.$
$Vậy...$