Answer:
[tex]a^2-16a+64[/tex]
Step-by-step explanation:
we have the options
[tex]a^2-18a+36\\a^2-16a+64\\a^2-8a+64\\a^2-6a+36[/tex]
the one that is a perfect equare tinomial is:
[tex]a^2-16a+64[/tex]
because we can rewrite this as follows:
[tex](a-8)^2[/tex] this is because we know that
[tex]x^2-2xy+y^2=(x-y)^2[/tex]
thus
[tex]a^2-16a+64=(x-8)^2[/tex]
and the other options cannot be represented as a perfect square trinomial, so the correct answer is:
[tex]a^2-16a+64[/tex]
