Answer
$(2z - 5)^2$
Work Step by Step
This exercise contains a perfect square trinomial, which follows the form $a^2 - 2ab + b^2 = (a - b)^2$.
According to this formula, we find the square root of the first and last terms, which are $2z$ and $5$, respectively.
Then we check to see if the middle term is two times the product of these two square roots, which it is.
Now, we can subtract the square roots from each other and then square the difference:
$(2z - 5)^2$