Find the Perfect Square Trinomial z^2-18z+

$z^{2} - 18 z +$

Step 1

To find the $c$ value $c = {(\frac{b}{2})}^{2}$ , divide the coefficient of $z$ by $2$ and square the result.

Divide $18$ by $2$ .

${(- 1 \cdot 9)}^{2}$

Multiply $- 1$ by $9$ .

${(- 9)}^{2}$

Raise $- 9$ to the power of $2$ .

$81$

Step 2

Add $81$ to get the perfect square trinomial.

$z^{2} - 18 z + 81$