$(x-1)²-5=31$
$⇒(x-1)²= 31+5$
$⇒(x-1)²=36$
$⇒\left[ \begin{array}{l}(x-1)^{2}=6^{2}\\(x-1)^{2}=(-6)^{2}\end{array} \right.$
$⇒\left[ \begin{array}{l}x-1=6\\x-1=-6\end{array} \right.$
$⇒\left[ \begin{array}{l}x=7\\x=-5\end{array} \right.$
Vậy x ∈ {7;-5}
$(x-2)³-1=26$
$⇒(x-2)³=27$
$⇒(x-2)³=3³$
$⇒x-2=3$
$⇒x=3+2=5$
Vậy x = 5
