For this case, we have that by definition, a perfect square trinomial, is a polynomial of three terms (also called trinomial) that results from squaring a binomial.
[tex](a + b) ^ 2 = a ^ 2 + 2ab + b ^ 2\\(a-b) ^ 2 = a ^ 2-2ab + b ^ 2[/tex]
We have:
[tex]4x ^ 2-20xy + 25y ^ 2\\(2x) ^ 2 = 4x ^ 2\\(5y) ^ 2 = 25y ^ 2[/tex]
So:
[tex]2 * 5y * 2x = 20xy[/tex]
So, [tex]4x ^ 2-20xy + 25y ^ 2[/tex]we can write it as:
[tex](2x-5y) ^ 2[/tex]
Answer:
Option A
