Đáp án:
$a, (x - 1)² = 0 $
$⇔ x - 1 = 0 $
$⇔ x = 1 $
$b, (x - 1)² = 1 $
$⇔$ \(\left[ \begin{array}{l}(x-1)^{2}=1^{2}\\(x-1)^{2}=(-1)^{2}\end{array} \right.\)
$⇔$ \(\left[ \begin{array}{l}x-1=1\\x-1=-1\end{array} \right.\)
$⇔$ \(\left[ \begin{array}{l}x=2\\x=0\end{array} \right.\)