d^2 + 18d + 81
This is a quadratic trinomial that can be factored as:
d^2 + 18d + 81 = (d + 9)(d + 9) = (d + 9)^2
So, d^2 + 18d + 81 can be written as (d + 9)^2.
d^2 + 18d + 81 = (d + 9)(d + 9) = (d + 9)^2
So, d^2 + 18d + 81 can be written as (d + 9)^2.