Factor y out of y3+18y2+81y.
Factor y out of y3.
Factor y out of 18y2.
Factor y out of 81y.
Factor y out of y⋅y2+y(18y).
Factor y out of y(y2+18y)+y⋅81.
Factor using the perfect square rule.
Rewrite 81 as 92.
Check that the middle term is two times the product of the numbers being squared in the first term and third term.
Rewrite the polynomial.
Factor using the perfect square trinomial rule a2+2ab+b2=(a+b)2, where a=y and b=9.