how do you figure out the square root of z^2+8z+16?

Step-by-step explanation:
Hey there!
Given;
[tex] = \sqrt{ {z}^{2} + 8z + 16} [/tex]
Looking through question, we can bring it to perfect square to remove the (√) sqrt.
[tex] \sqrt{( {z)}^{2} + 2.4x + {4}^{2} } [/tex]
We made this to bring it in the form of (a+b)^2. As (a+b)^2 = a^2 + 2.a.b + b^2.
Now, our question looks like similar to the formula.
So, We can write it as:
[tex] \sqrt{( {z + 4)}^{2} } [/tex]
Now, we can cancel (√) and (^2). And we get
= z + 4
Hope it helps...