Answer:The first negative number does not have brackets because it is easily recognized as a negative number. The following negative numbers DO have brackets to separate the negative sign on the number from the addition/subtraction operand sign in the question.
Although brackets do mean: "do this first" it doesn't apply here because there are no operations within the brackets.
Aboslute value brackets look like this |x-y| not like this (x-y). Please don't confuse them commenters.
Step-by-step explanation: