Answer
This is the case because the absolute value of a negative number is positive.
Work Step by Step
We know that taking the absolute value of a negative number will make the answer positive. Also, we know that a given number is a solution if and only if it satisfies the initial equation. Furthermore, if the absolute value of x is equal to a number a, we know that plugging both a and -a into the equation will satisfy it. Thus, saying that the absolute value of x equals a is the same as saying that x=a and x=-a.
