Question

How do you factor completely `z^2 + 36z + 324`?

Answer 1

`z^2+36z+324 = z^2+2(18z)+18^2 = (z+18)^2`

Explanation:

This is a perfect square trinomial: `18^2=324` and `36=2*18`, so we find:

`z^2+36z+324 = z^2+2(18z)+18^2 = (z+18)^2`