Chapter 11 - Section 11.4 - Partial Sums of Arithmetic and Geometric Sequences - Exercise Set - Page 660: 56

$27x^3+54x^2+36x+8$

Using $(a+b)^3=a^3+3a^2b+3ab^2+b^3$ (or the cube of a binomial), the given expression, $ (3x+2)^3 ,$ is equivalent to \begin{array}{l}\require{cancel} (3x)^3+3(3x)^2(2)+3(3x)(2)^2+(2)^3 \\\\= 27x^3+3(9x^2)(2)+3(3x)(4)+8 \\\\= 27x^3+54x^2+36x+8 .\end{array}