Question

Which trinomial is a perfect square trinomial? a2 – 18a + 36 a2 – 16a + 64 a2 – 8a + 64 a2 – 6a + 36

Answer 1

`a^2-16a+64`

Explanation:

we have the options

`a^2-18a+36\\a^2-16a+64\\a^2-8a+64\\a^2-6a+36`

the one that is a perfect equare tinomial is:

`a^2-16a+64`

because we can rewrite this as follows:

`(a-8)^2` this is because we know that

`x^2-2xy+y^2=(x-y)^2`

thus

`a^2-16a+64=(x-8)^2`

and the other options cannot be represented as a perfect square trinomial, so the correct answer is:

`a^2-16a+64`