Solve.

|x-|1=3
Select the correct choice below and, if necessary, fill in the answer box to complete your choice.
• A. The solution set is
3. (Use a comma to separate answers as needed.)
• B. The solution is the empty set.

To solve the equation |x-|1|=3, we can start by simplifying the expression inside the outer absolute value.

|x-|1|=3

|x-1|=3

Now, we can set up two separate equations, one for when x-1 is positive and one for when x-1 is negative.

When x-1 is positive:
x-1 = 3

Solving for x, we add 1 to both sides:
x = 4

When x-1 is negative:
x-1 = -3

Solving for x, we add 1 to both sides:
x = -2

Therefore, the solution set is {4, -2}.

A. The solution set is 4, -2.