For example in the 'lines' |27| it represents the number. if it were let's say |-7| to "simplify" it would make it 7. if it were |7| it would be 7. and if it was let's say -|7| it is -7 because you do |7| but the negative is in front of it still causing it to be negative. if it were -|-7| you'd do what's in the lines/parentheses so it would be - 7 so you'd have to move the negative in front of the 7 to make it negative so your answer is -7