Answer:
34a^3
Explanation:
Since every term is alike we can add and subtract freely
(I wont be writing a^3 on every term to make this less confusing)
17 + 19 - 25 - (-17 + 19 - 25)
first the parenthesis do what is inside the parenthesis
17 + 19 - 25 - (-23)
now add everything
11 - (-23)
simplify
11 + 23
34
everything of course has a^3 at the end so
34a^3 is the answer