z^2-18z+81-25x^2

Question

(z-9)^2 -(5x)^2
(z-9+5x)(z-9-5x)

is this factored completely?

Answer 1

where's the 18z? it's set up as multiplication.

Answer 2

isn't the (z-9)^2 for the 18?

not sure how to finish it then

Answer 3

z^2 – 18z – 37 = 0