Answer:
16x^2 -8x +1
Step-by-step explanation:
The square of a binomial expands as ...
(a +b)^2 = a^2 +2ab +b^2
So, you need to look for a trinomial with first and last terms that are perfect squares and a middle term that is double the product of the roots of those terms.
This pattern matches ...
16x^2 -8x +1 = (4x -1)^2
