Explain Expressions ?

"One set of absolute value signs can only take the absolute value of one number."

For example,

For the absolute value of negative six plus three, convert the two numbers into one number by first adding negative six and three. The result is one number, negative three. Then take the absolute value of negative three. The answer is 3.

The wrong way is to take the absolute value of negative six and three, resulting in the absolute value of six plus three. This is incorrect, because the same set of absolute value signs is doing its job to two numbers. The rule is: "One set of absolute value signs can only take the absolute value of one number."

|-6 +| = |-3| = 3 (Correct!)
|-6+ 3| = |6+3| =9 (Wrong!)