Which of the following xpressions is equivalent to - 1/4 - 5/3? - 1/4 + (-5/3) or - 1/4 + 5/3?

-1/4 + (-5/3)

When there is no number between a grouping symbol and a + or - sign, by default you can multiply the contents in the group by 1 to get rid of the grouping symbols.