Factor x2+18x+81x^2 + 18x + 81x2+18x+81.
(x+9)2(x + 9)^2(x+9)2
(x+6)(x+13.5)(x + 6)(x + 13.5)(x+6)(x+13.5)
(x+9)(x+1)(x + 9)(x + 1)(x+9)(x+1)
(x+3)(x+27)(x + 3)(x + 27)(x+3)(x+27)