Answer
{$-1, 3$}
Work Step by Step
Using Property 10.1, which states that for any non-negative real number $a$, $(x-b)^{2}=a$ can be written as $x-b=\pm\sqrt a$, we obtain:
Step 1: $(x-1)^{2}=4$
Step 2: $x-1=\pm \sqrt 4$
Step 3: $x-1=\pm 2$
Step 4: $x-1=2$ or $x-1=-2$
Step 5: $x=2+1$ or $x=-2+1$
Step 6: $x=3$ or $x=-1$
The solution set is {$-1, 3$}.