Answer: -125p12z18u3
Reason:
Square negative five twice, so: -5 x -5 x -5 = -125
The first squaring is -5 x -5, which is 25. The second squaring is 25 x (-5), which is - 125.
When it comes to the letters, they act like they are being multiplied.
(p4)3 = p12
(z6)3 = z18
(u)3 = u3
So the answer is -125p12z18u3.
Hope this helps! :)