a) 5 - |3x - 1| = 3
⇒ |3x - 1| = 5 - 3
⇒ |3x - 1| = 2
⇒ $\left[ \begin{array}{l}3x - 1 = 2\\3x - 1=-2\end{array} \right.$
⇒ $\left[ \begin{array}{l}3x = 3 \\3x = -1\end{array} \right.$
⇒ x = 1
x = $\dfrac{-1}{3}$
b) (1 - 2x)² = 9
⇒ (1 - 2x)² = 3²
⇒ $\left[ \begin{array}{l}1 - 2x = 3\\1 - 2x=-3\end{array} \right.$
⇒ $\left[ \begin{array}{l} 2x = -2\\2x= -4\end{array} \right.$
⇒ $\left[ \begin{array}{l} x = -1\\x= -2\end{array} \right.$
