a) $(x-\dfrac{1}{2})^2=0$
$↔x-\dfrac{1}{2}=0$
$↔x=0+\dfrac{1}{2}=\dfrac{1}{2}$
b) $(x-2)^2=1$
TH1: $x-2=1$
$→x=1+2=3$
TH2: $x-2=-1$
$→x=-1+2=1$
c) $(2x-1)^3=-8$
$↔2x-1=-2$
$↔2x=-2+1=-1$
$↔x=-\dfrac{1}{2}$
d) $(x+\dfrac{1}{2})^2=\dfrac{1}{16}$
TH1: $x+\dfrac{1}{2}=\dfrac{1}{4}$
$↔x=\dfrac{1}{4}-\dfrac{1}{2}$
$↔x=\dfrac{1}{4}-\dfrac{2}{4}$
$↔x=-\dfrac{1}{4}$
TH2: $x+\dfrac{1}{2}=-\dfrac{1}{4}$
$↔x=-\dfrac{1}{4}-\dfrac{1}{2}$
$↔x=-\dfrac{1}{4}-\dfrac{2}{4}$
$↔x=-\dfrac{3}{4}$
