Use the form , to find the values of , , and .

Consider the vertex form of a parabola.

Substitute the values of and into the formula .

Cancel the common factor of and .

Factor out of .

Cancel the common factors.

Factor out of .

Cancel the common factor.

Rewrite the expression.

Divide by .

Multiply by .

Simplify each term.

Raise to the power of .

Multiply by .

Divide by .

Multiply by .

Subtract from .

Substitute the values of , , and into the vertex form .

Complete the Square z^2-18z